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'''Transition metal oxides''' are compounds composed of [[oxygen]] atoms bound to [[transition metals]]. They are commonly utilized for their [[catalysis|catalytic]] activity and [[semiconductor|semiconductive]] properties. Transition metal oxides are also frequently used as pigments in paints and plastics, most notably [[titanium dioxide]]. Transition metal oxides have a wide variety of surface structures which affect the surface energy of these compounds and influence their chemical properties. The relative acidity and basicity of the atoms present on the surface of metal oxides is also affected by the coordination of the metal [[cations|cation]] and oxygen [[anions|anion]], which alter the catalytic properties of these compounds. For this reason, structural defects in transition metal oxides greatly influence their catalytic properties. The acidic and basic sites on the surface of metal oxides are commonly characterized via [[infrared spectroscopy]], [[calorimetry]] among other techniques. Transition metal oxides are also able to undergo photo-assisted [[adsorption]] and [[desorption]] to control their semiconductivity. One of the more researched properties of these compounds is their response to [[electromagnetic radiation]], which makes them useful catalysts for redox reactions, isotope exchange, specialized surfaces and a variety of other uses currently being studied.
 
==Surface structure and stability==
There is very little known about the surface structures of transition [[Metal oxide adhesion|metal oxides]], but their bulk crystal structures are well researched. The approach to determine the surface structure is to assume the oxides are ideal crystal, where the bulk atomic arrangement is maintained up to and including the surface plane. The surfaces will be generated by [[Cleavage (crystal)|cleavages]] along the planes of the bulk crystal structure.<ref name=henrich>{{cite book|last=Henrich|first=V.E.|title=The Surface Science of Metal Oxides|year=1994|publisher=Cambridge University Press|location=New York|pages=14–61}}</ref> However, when a crystal is cleaved along a particular plane, the position of surface ions will differ from the bulk structure. Newly created surfaces will tend to minimize the [[Gibbs free energy|surface Gibbs energy]], through [[Surface reconstruction|reconstruction]], to obtain the most thermodynamically stable surface.<ref name=kung>{{cite book|last=Kung|first=H|title=Transition Metal Oxides: Surface Chemistry and Catalysis|year=1989|publisher=Elsevier|location=Amsterdam}}</ref> The stability of these surface structures are evaluated by [[Chemical polarity|surface polarity]], the [[Saturation (chemistry)|degree of coordinative unsaturation]] and defect sites.
 
===Bulk structures===
The oxide [[crystal structure]] is based on a closed-pack array of oxygen anions, with metal cations occupying interstitial sites.<ref name=henrich/> The close-packed arrays, such as [[Cubic crystal system|face-centered-cubic (fcc)]] and [[Cubic crystal system|hexagonal-close packed (hcp)]], have both octahedral and tetrahedral interstices. [http://www.seas.upenn.edu/~chem101/sschem/ionicsolids.html#typessites]
 
====Monoxides====
The first row of transition metal monoxides (MO), [[TiO]] to [[NiO]], have a [[Cubic crystal system|rocksalt structure]]. The rock salt structure [http://www.seas.upenn.edu/~chem101/sschem/ionicsolids.html#rocksalt] is generated by filling all [[octahedral]] sites with cations in an oxygen anion [[Cubic crystal system|fcc array]].<ref name =solid>{{cite book|last=West|first=A|title=Basic Solid State Chemistry|year=2000|publisher=Wiley|location=New York}}</ref><ref name=ionic>{{cite web|last=EveryScience|title=Ionic Solids|url=http://www.everyscience.com/Chemistry/Inorganic/Ionic_Solids/b.1297.php|accessdate=7 June 2011}}</ref>
 
====Dioxides====
[[File:RutileTiO2angles.png|thumb|The [[rutile]] crystal structure of TiO<sub>2</sub>]]
The majority of transition metal dioxides (MO<sub>2</sub>) have the [[Rutile|rutile structure]], seen to the right. Materials of this [[stoichiometry]] exist for Ti, Cr, V and Mn in the first row transition metal and for Zr to Pd in the second. The rutile structure is generated by filling half of the octahedral sites with cations of the [[Close-packing of spheres|hcp oxygen anion array]].<ref name=solid /><ref name=ionic/>
 
====Trioxides====
Few transition metals can achieve the +6 oxidation state in an oxide, so oxides with the stoichiometry MO<sub>3</sub> are rare.<ref name=struct />
 
====Ternary oxides====
The structure of [[Binary compound|binary]] oxides can be predicted on the basis of the relative sizes of the metal and oxide ions and the filling of holes in a close packed oxide lattice. However, the predictions of structure are more difficult for [[Ternary compound|ternary]] oxides. The combination of two or more metals in an oxide creates a lot of structural possibilities. Also, the stoichiometry of ternary oxide may be changed by varying the proportions of the two components and their [[oxidation state]]s. For example, at least twenty ternary oxide phases are formed between strontium and vanadium including SrV<sub>2</sub>O<sub>6</sub>, Sr<sub>2</sub>V<sub>2</sub>O<sub>5</sub>, SrVO<sub>3</sub> and Sr<sub>2</sub>VO<sub>4</sub>.<ref name=struct>{{cite web|last=Weller|first=Mark|title=Transition Metal Oxides|url=http://www.azmax.co.jp/idx02_product/siyaku/pdf_plus/H/Materials-004.pdf|publisher=University of Southampton|accessdate=7 June 2011}}</ref> The structural chemistry of ternary and more complex oxides is an extensive subject, but there are a few structures that are widely adopted by ternary oxides, such as the perovskite structure.
 
=====Perovskite structure=====
The [[Perovskite (structure)|perovskite structure]], ABO<sub>3</sub>, is the most widespread ternary phase. The perovskite structure is frequently found for ternary oxides formed with one large (A) and one small cation (B). In this structure, there is a simple cubic array of B cations, with the A cations occupying the center of the cube, and the oxide atoms are sited at the center of the 12 edges of the simple cube.[http://cst-www.nrl.navy.mil/lattice/struk/perovskite.html] <ref name=solid /><ref name=ionic/><ref name=struct/>
 
===Surface stability===
Since very little is known about the surface Gibbs energy of transition metal oxides, polarity of the surface and the degree of coordinative unsaturation of a surface cation are used to compare the stabilities of different surface structures.<ref name=kung /> Also, defect sites can have a huge impact on the surface stability.
 
====Polarity of the surface ====
When a crystal of a binary oxide is cleaved to generate two new surfaces, each solid’s charge remains neutral. However, the structure of the two newly created surfaces may or may not be the same. If the structures are identical, the surface will be [[Electric dipole moment|dipoleless]] and is considered a nonpolar surface. If the structures are different, the surface will have a strong [[Electric dipole moment|dipole]] and is considered a polar surface. Examples of nonpolar surfaces include the rocksalt (100) surface, the rutile (100), (110) and (001) surfaces and the pervoskite (100) surface.<ref name=kung /> An example of a polar surface is the rocksalt (111) surface.<ref name=kung /> In general, a polar surface is less stable than a nonpolar surface because a dipole moment increases the surface Gibbs energy. Also, oxygen polar surfaces are more stable than metal polar surfaces because oxygen ions are more [[Polarizability|polarizable]], which lowers the surface energy.<ref>{{cite journal|last=Al-Abadleh|first=Hind|coauthors=Grassian|title=Oxide surfaces as environmental interfaces|journal=Surface Science Reports|year=2003|volume=52|pages=63–161|doi=10.1016/j.surfrep.2003.09.001|issue=3–4}}</ref>
 
====The degree of coordinative unsaturation of a surface cation====
[[Saturation (chemistry)|The degree of coordinative unsaturation]] of a surface cation measures the number of bonds involving the cation that have to be broken to form a surface.<ref name=kung /> As the degree of coordinative unsaturation increases, more bonds are broken and the metal cation becomes destabilized. The destabilization of the cation increases the surface Gibbs energy, which decreases the overall stability. For example, the rutile (110) surface is more stable than the rutile (100) and (001) surfaces because it has a lower degree of coordinative unsaturation.<ref name=kung />
 
====Defect sites====
[[File:NIO defect surface.jpeg|thumb|NiO rock salt crystal showing cation and oxygen vacancies.]]
Defect sites can interfere with the stability of metal oxide surfaces, so it is important to locate and determine methods to control these sites. Oxides exhibit an abundance of [[Crystallographic defect|point defect sites.]]
In rocksalt surfaces, oxygen and metal cation [[Vacancy defect|vacancies]] are the most common point defects. The vacancies are produced by [[Electron ionization|electron bombardment]] and [[Annealing (metallurgy)|annealing]] to extremely high temperatures. However, oxygen vacancies are more common and have a greater impact than metal cation vacancies. Oxygen vacancies cause reduction in between surface cations, which significantly affect the electronic energy levels.<ref name= defect>{{cite book|last=Henrich|first=V|title=Surface and Near-surface Chemistry of Oxide Materials|year=1988|publisher=Elsevier|location=Amsterdam|pages=23–30}}</ref> [[Carrier scattering|Steps and kinks]] are two other defects that impact rocksalt surfaces. These structural defects reduce the coordination environment of the four adjacent surface cations from 5 to 4.<ref>{{cite journal|last=Liu|first=P|coauthors=Kendelewicz|journal=Surface Science|year=1998|pages=315|doi=10.1016/S0039-6028(98)00445-2|title=Reaction of water with MgO(100) surfaces. Part II:|volume=412–413}}</ref>
In rutile surfaces, the most common type of defect is oxygen vacancies. There are two types of oxygen vacancies, which result from either the removal of a bridging O<sup>2-</sup> ions or the removal of an inplane O<sup>2-</sup> ion. Both of these will reduce the coordination of the surface cations.[http://www.ndt-ed.org/EducationResources/CommunityCollege/Materials/Structure/point_defects.htm]<ref name=defect/><ref>{{cite journal|last=Bart|first=F|coauthors=Gautier|journal=Surface Science|year=1994|doi=10.1016/0039-6028(94)90471-5|title=A LEED study of the (0001) a-quartz surface reconstruction|volume=311|pages=L671}}</ref>
 
== Surface acidity/basicity ==
=== Extension of acid/base theories to solids ===
The surface of a metal oxide consists of ordered arrays of acid-base centres. The cationic metal centres act as Lewis acid sites while the anionic oxygen centres act as Lewis bases. Surface Hydroxyl groups are able to serve as Brønsted acid or base sites as they are able to give up or accept a proton.<ref name =glazneva>{{cite journal | author= T.S. Glazneva, N.S. Kotsarenko, E.A. Paukshtis | journal= Kinetics and Catalysis | year=2008 | volume= 49 | pages= 856–867| doi=10.1134/S0023158408060104 | title= Surface acidity and basicity of oxide catalysts: From aqueous suspensions to in situ measurements | issue= 6}}</ref> The surface of most metal oxides will be, to some extent, hydroxylated under normal conditions when water vapor is present.<ref name= boehm>{{cite journal | author=H.P> Boehm | journal=Discussions of the Faraday Society | year=1971 | volume=52 | pages=264–275 | doi=10.1039/df9715200264 | title=Acidic and basic properties of hydroxylated metal oxide surfaces}}</ref> The strength and the amount of Lewis And Brønsted acid-base sites will determine the catalytic activity of many metal oxides. Due to this there is a great need to develop standard methods for the characterization of the strength, concentration, and distribution of surface acid-base sites.<ref name=glazneva/>
 
The concepts of [[Lewis acid-base theory]] and [[Brønsted-Lowry acid-base theory]] may be applied to surfaces, however there is no general theory that serves to determine surface acidity or basicity.<ref name= dis>M. W. Abee, “Interaction of acid/base probe molecules with specific features on well-defined metal oxide single-crystal surfaces,” Dissertation, Blacksburg, Virginia (2001)</ref> The qualitative treatment of Brønsted acid base theory is based on the thermodynamic [[equilibrium constant]] (K<sub>a</sub>) of acid-base reactions between individual molecules in homogeneous systems. This treatment requires measurement of equilibrium concentrations of reactants and products. The presence of two phases also provides a problem for the quantitative acid-base determination of solids. When an acid or base is adsorbed on to an oxide surface it will perturb neighbouring acid-base sites.<ref name= genconcepts>{{cite journal | author=Adriano Zecchina, Carlo Lamberti, Silvia Bordiga | journal=Catalysis Today | year=1998 | volume=41 | pages=169–177 | doi=10.1016/S0920-5861(98)00047-9 | title=Surface acidity and basicity: General concepts}}</ref> This perturbation will inevitably influence the [[surface reconstruction|relaxation]] of the surface and make it impossible to have acid-base reactions at the surface which only involve a single surface site.
 
=== Structural relation to surface acidity/basicity ===
For metal oxides acidity and basicity are dependent on the charge and the radius of the metal ions as well as the character of the metal oxygen bond. The bond between oxygen and the metal is influenced by the coordination of the metal cations and the oxygen anions as well as the filling of the metal d-orbitals.<ref name=dis/> The surface coordination is controlled by the face that is exposed and by the surface relaxation.  Structural defects can greatly contribute to the acidity or basicity as sites of high unsaturation can occur from oxygen or metal ion vacancies.
 
=== Methods of determining surface acidity/basicity ===
====Indicator method====
 
Adsorption of an indicator molecule was first proposed by Hammett for ordering the strength of solid acids and bases.<ref name=glazneva/> This technique is only applicable to surface Brønsted sites on metal oxides. According to Hammett, the strength of a Brønsted surface site can be determined by the [[Hammett acidity function]],
 
<math> H_o = pK_{BH^+} -log \frac{[BH^+]}{[B]} </math>
 
where B is the basic indicator molecule. The concentration of Brønsted acid sites can be determined by titrating a suspension of the oxide with an acid/base indicator present.<ref name=glazneva/> However, this method is subject to many problems. For instance only Bronsted acid sites can be quantified with this method. Metal oxide surfaces can have both Brønsted and Lewis acid sites present at the same time which leads to a nonspecific interaction between the oxide and the indicator.<ref name= dis/> Also, as outlined in the theory section, the perturbation of neighboring sites upon adsorption of indicator molecules compromises the integrity of this model.<ref name= genconcepts/>
 
====IR determination of adsorbed probe molecules====
 
The [[adsorption]] of a very weakly basic or acidic probe molecule can serve to give a picture of Brønsted and Lewis acid-base sites. [[Infrared spectroscopy]] of surface sites and adsorbed molecules can then be used to monitor the change in the vibrational frequencies upon adsorption.<ref name=glazneva/> A very weakly acidic probe molecule can be used to minimize disturbing neighboring sites so that a more accurate measure of surface acidity or basicity can be obtained. A variety of probe molecules can be used including: [[ammonia]], [[pyridine]], [[acetonitrile]], [[carbon monoxide]], and [[carbon dioxide]].<ref name=glazneva/><ref name=dis/>
 
====Calorimetric and thermal desorption====
 
Two promising methods for the description of the acid-base properties of metal oxides are Calorimetric measurements of adsorption enthalpies and [[Thermal desorption spectroscopy|Temperature Programed desorption]].<ref name=dis/> The measurement of the heat of [[adsorption]] of basic or acidic probe molecules can give a description of acidic and basic sites on metal oxide surfaces. Temperature programed desorption provides information about acid-base properties by saturating the surface with a probe molecule and measuring the amount that desorbs from the surface as a function of temperature. The calorimetric method provides a quantitative thermodynamic scale of acetate properties by measuring the heat of adsorption. Calorimetric methods can be considered to give a measure of the total acidity or basicity as it is not descriminate to either Lewis or Brønsted sites. However, when differential heats of adsorption are combined with other techniques, such as IR spectroscopy, the nature and distribution of acid-base adsorption sites can be obtained.<ref name= auroux>{{cite journal | author= Aline Auroux, Antonella Gervasin| journal=J. Phys. Chem. | year=1900 | volume=94| pages=6371–6379 }}</ref>
 
=== Case study of surface acidity/basicity===
====ZrO<sub>2</sub>====
[[File:Zn.jpeg|thumb|representation of the zirconia surface]]
[[Zirconia]] exists in the [[monoclinic]], [[tetragonal]] or [[cubic crystal system|cubic]] crystal system depending on the temperature. The surface acidity and bascity of the oxide is dependent on which phase is present and which crystal face is showing.<ref name=zro>{{cite journal | author=Konstantin Pokrovski, Kyeong T. Jung, Alexis T. Bel | journal=Langmuir | year=2001 | volume=17 | pages=4297–4303 | doi=10.1021/la001723z | title=Investigation of CO and CO2Adsorption on Tetragonal and Monoclinic Zirconia | issue=14}}</ref> The surfaces of Zirconia have hydroxyl groups, which can act as Brønsted acids or bases, and coordination-unsaturated Zr<sup>4+</sup>O<sup>2-</sup> acid base pairs which contribute to its overall acid-base properties.<ref name=zro/> Adsorption studies have shown that monoclinic zirconia is more basic than tetragonal, as it forms stronger bonds with CO<sub>2</sub>. Adsorption of CO shows that the tetragonal phase has more acidic Lewis acid sites than the monoclinic phase, but that it has a lower concentration of Lewis acid sites.<ref name=zro/>
 
== Photoassisted processes ==
=== Electronic band structure ===
The bulk electronic band structure of transition metal oxides consists of overlapping 2p orbitals from oxygen atoms, forming the lower energy, highly populated valence band, while the sparsely populated, higher energy conduction band consists of overlapping d orbitals of the transition metal cation.<ref name=Photocom>{{cite journal|last=Miyauchi|first=Masahiro|coauthors=Akira Nakajima, Akira Fujishima, Kazuhito Hashimoto, Toshiya Watanabe|title=Photoinduced Surface Reactions on TiO2 and SrTiO3 Films: Photocatalytic Oxidation and Photoinduced Hydrophilicity| journal= Chem. Mater |year=1999 |volume=12 |pages=3–5|doi=10.1021/cm990556p
}}</ref> In contrast to metals, having a continuous band of electronic states, semiconductors have a band gap that prevents the recombination of electron/hole pairs that have been separated into the conduction band/ valence band. The nanosecond scale life times of these [[electron]]/[[electron hole|hole]] separations allows for charge transfer to occur with an adsorbed species on the semiconductor surface. The Potential of an acceptor must be more positive than the conduction band potential of the semiconductor in order for reduction of the species to commence. Conversely, the potential of the donor species must be more negative than that of the valence band of the [[semiconductor]] for oxidation of the species to occur.<ref name="Long photo review" />
 
Near the surface of a semi-conducting metal oxide the valence and conduction bands are of higher energy, causing the upward bending of the band energy as shown in the band energy diagram, such that promotion of an electron from the valence band to the conduction band by light of energy greater than the band gap results in migration of the electron towards the bulk of the solid or to a counter electrode, while the hole left in the valence band moves towards the surface. The increased concentration of holes near the surface facilitates electron transfer to the solid, such as the example shown in the figure of the oxidation of redox couple D-/D.<ref name=Photometalbook>{{cite book|last=Kung|first=Harold|title=Transition Metal Oxides: Surface Chemistry and Catalysis|year=1989|publisher=Elsevier Science Publishers B.V.|location=Amsterdam|pages=252–272}}</ref> In the absence of any mechanism to remove electrons from the bulk of the solid irradiation continues to excite electrons to the conduction band producing holes in the valence band. This leads to the reduction of the upward [[band bending|bending of the band energies]] near the surface, and the subsequent increase in excited electron availability for reduction reactions.<ref name=Photometalbook />
[[File:Excitation of a transition metal oxide.png|thumb|This [[band diagram]] shows the excitation of an electron to the conduction band, and the reaction of a hole in the valence band with a redox couple at the surface of the solid.]]
The following equations are useful in describing the populations of valence and conduction bands in terms of holes and electrons for the bulk metal. <math>n</math> is the density of electrons in the bulk metal conduction band, and <math>p</math> is the density of holes in the bulk metal valence band. E<sub>c</sub> is the lowest energy of the conduction band,E<sub>f</sub> is the Fermi energy(electrochemical energy of the electrons), E<sub>v</sub> is the highest energy of the valence band, N<sub>c</sub> is the effective mass and mobility of an electron in the conduction band (constant), and N<sub>v</sub> is the effective mass and mobility of a valence band hole (constant).<ref name=Photometalbook />
 
<math>n=N_{c}e^{\frac{-(E_c - E_f)}{kT}}</math>
 
<math>p=N_{v}e^{\frac{-(E_{f}-E_{v})}{kT}}</math>
 
Where k is [[Boltzmanns constant]] and T is the absolute temperature in Kelvin.
 
The use of quantum mechanics [[perturbation theory]] can aid in calculating the probability of an electronic transition taking place. The probability is proportional to the square of the amplitude of the radiation field, E<sub>0</sub>, and the square of the transition dipole moment |μ<sub>if</sub>|.<ref name="Long photo review" />
 
<math>P \propto {E_o}^2 {|\mu_{if}|}^2 </math>
 
The quantum yield for an ideal system undergoing photocatatalytic events is measured as the number of events occurring per photon absorbed. The typical assumption in determining the quantum yield is that all photons are absorbed on the semiconductor surface, and the quantum yield is referred to as the apparent quantum yield. This assumption is necessary due to the difficulty in measuring the actual photons absorbed by the solid surface. The relation between the quantum yield, the rate of charge transfer, k<sub>CT</sub>, and the electron/hole recombination rate, k<sub>R</sub>, is given by the following equation.<ref name="Long photo review" />
 
<math>\Phi \propto {\frac{k_{CT}}{(k_{CT}+k_R)}}</math>
 
Photoinduced molecular transformations at transition metal oxide surfaces can be organized in two general classes. Photoexcitation of the adsorbate which then reacts with the catalyst substrate is classified as a catalyzed photoreaction. Photoexcitation of the catalyst followed by interaction of the catalyst with a ground state reactant is classified as a sensitized photoreaction.<ref name="Long photo review">{{cite journal|last=Linsebigler|first=Amy|coauthors=Guangquan Lu, John T. Yates Jr.|title=Photocatalysis on TiO2 Surfaces: Principles, Mechanisms, and Selected Results|journal=Chem. Rev.|year=1994|volume=95|pages=735–758|doi=10.1021/cr00035a013|url=http://image.sciencenet.cn/olddata/kexue.com.cn/blog/admin//images/upfiles/200710117325893655.pdf }}</ref>
 
=== Photoassisted adsorption and desorption ===
[[Adsorption]] and [[desorption]] can both be promoted by exposure of trans metal oxides to light, the predominant process being controlled by experimental conditions. Adsorption of [[oxygen]] by illumination of TiO<sub>2</sub> or [[ZnO]] at room temperature with low pressure results in the adsorption of oxygen, while at high pressures illumination leads to photo-assisted desorption. At high temperatures the opposite effect is observed, with low pressure leading to desorption, and high pressure causing adsorption.<ref name=Photometalbook /><ref name="NO ad ZnO">{{cite journal|last=Kase|first=K.|coauthors=M. Yamaguchi, T. Suzuki, K. Kaneko|title=Photoassisted Chemisorption of NO on ZnO|journal=Journal of Physical Chemistry|year=1995|volume=99|issue=36|pages=13307–13309|doi=10.1021/j100036a002}}</ref>
Kase, Yamaguchi, Suzuki, and Kaneko conducted a study of the photo-assisted [[chemisorption]] of NO on ZnO, finding that under dark conditions a negligible amount of [[Nitric oxide|NO]] adsorbed to the metal oxide, however under illumination they found that ZnO irreversibly adsorbs NO, their sample showing no desorption after irradiation had stopped.<ref name="NO ad ZnO" />
 
The process by which adsorption and desorption on metal oxide surfaces takes place is related to the photo generation of holes on the solid surface, which are believed to be trapped by hydroxyl groups on the surface of a transition metal oxides.<ref name="Long photo review" /><ref name="NO ad ZnO" /> These trapped holes allow photo excited electrons to be available for chemisorption.<ref name="NO ad ZnO" /> Doping of a cation of either higher or lower valence can change the electronic properties of the metal oxide.Doping with a higher valence cation typically results in an increase in ''n''-type semi-conductivity, or raises its Fermi energy, whiledoping with a lower valence cation should lower the fermi energy level and reduce the metal oxides ''n''-type semi-conductivity.<ref name="Altervalent cation doping" /> The process of doping indicates that a cation other than the transition metal cation experienced in the majority of the bulk is incorporated into the crystal structure of the semiconductor, either by replacing the cation, or interstitially adding to the matrix.<ref name="Altervalent cation doping">{{cite journal|last=Ioannides|first=Theophilos|coauthors=Xenophon E. Verykios|title=Effects of altervalent cation doping of TiO2 on H2 and CO adsorption on supported Rh|journal=Journal of Catalysis|year=1993|volume=145|pages=479–490}}</ref> Doping of ZnO with Li leads to greater photo adsorption of oxygen, while doping with Ga or Al suppresses photo adsorption of oxygen. Trends in photo adsorption tend to follow trends in photo oxidative catalysis, as shown by TiO<sub>2</sub>’s and ZnO’s high degree of photo oxidative catalysis, while other transition elements like V<sub>2</sub>O<sub>5</sub> shows no photo oxidative catalytic response as well as no photo activated adsorption of oxygen.<ref name=Photometalbook />
 
=== Liquid-phase photocatalysis ===
One of the most exciting and most studied uses of photo catalysis is the photo-oxidation of organics as it applies to environmental decontamination.<ref name=Photocom />
In contrast to gas phase interactions with the solid surface, the vast number of variables associated with the liquid solid interface (i.e. solution pH, photocatalyst concentration, solvent effects, diffusion rate, etc.) calls for greater care to be taken to control these variables to produce consistent experimental results.<ref name=Photocom /><ref name="Long photo review" /> A greater variety of reactions also become possible due to the ability of solutions to stabalize charged species, making it possible to add an electron from the metal to a neutral species producing an anion that can go on to further react, or a hole to remove an electron, producing a cation that goes on to further react in solution.<ref name=Photometalbook />
 
====Oxidation====
One mechanism proposed for the oxidation of adsorbed organics from solution is the production of hydroxyl radical by the valence holes migrating to the surface and reacting with adsorbed hydroxyl groups, resulting in a very strong oxidizing radical. Identification of hydroxylated oxidation intermediates and hydroxyl radicals supports this proposed mechanism, however this does not negate the possibility of the direct oxidation of the organic reactant by the valence holes because similar intermediates would be expected in either case.<ref name="Long photo review" /> A few of the many Photo oxidation reactions possible are shown bellow.
 
{| class="wikitable"
|-
! Starting material !! Photo-oxidized product!! Metal oxide catalyst
|-
| C<sub>2</sub>O<sub>4</sub><sup>2-</sup> + O<sub>2</sub> + 2 H<sub>2</sub>O|| 2 CO<sub>2</sub> + 2 OH<sup>-</sup> + H<sub>2</sub>O<sub>2</sub>|| ZnO <ref name=Photometalbook />
|-
| (CH<sub>3</sub>)<sub>2</sub>CHOH + O<sub>2</sub> || (CH<sub>3</sub>)<sub>2</sub>CO + H<sub>2</sub>O<sub>2</sub>|| ZnO <ref name=Photometalbook />
|-
| CH<sub>3</sub>CO<sub>2</sub><sup>-</sup> + h<sup>+</sup> || C<sub>2</sub>H<sub>6</sub> + CO<sub>2</sub>|| Rutile TiO<sub>2</sub> <ref name=Photometalbook />
|-
|H<sub>2</sub>O || H<sub>2</sub> + <math>1/2</math>O<sub>2</sub> || RuO<sub>2</sub>-TiO<sub>2</sub>-Pt <ref name="Long photo review" />
|}
 
====Reduction====
In photo reduction the promoted electron of the metal oxide is accepted by an acceptor species. In the case of CO<sub>2</sub> reduction, shown in the table bellow, the absence of dissolved oxygen in the aqueous system favors reduction of protons to form Hydrogen radicals which then go on to reduce CO<sub>2</sub> to HCOOH. HCOOH can then be further reduced to HCOH and water. Further reduction leads to the production of CH<sub>3</sub><sup>•</sup> that can combine in a number of ways to produce CH<sub>4</sub> or C<sub>2</sub>H<sub>6</sub>, etc.<ref name="Reducing CO2" />
{| class="wikitable"
|-
! Starting material !! Reduction product !! Metal oxide
|-
| Cu<sup>2+</sup> || Cu<sup>0</sup> || TiO<sub>2</sub> <ref name=Photometalbook />
|-
| Pt<sup>4+</sup> || Pt<sup>0</sup> || TiO<sub>2</sub> <ref name=Photometalbook />
|-
| Cr(VI) || Cr(III) || TiO<sub>2</sub> or SO<sub>4</sub><sup>2-</sup>/TiO<sub>2</sub> <ref name="Cr reduction TiO2">{{cite journal|last=Jiang|first=Fang|coauthors=Zheng Zheng, Zhaoyi Xu, Shourong Zheng, Zhaobing Guo, Liquiang Chen|title=Aqueous Cr(VI) Photo-Reduction Catalyzed by TiO2 and Sulfated TiO2|journal=Journal of Hazardous Materials|year=2006|volume=134|issue=1–3|pages=94–103|doi=10.1016/j.jhazmat.2005.10.041|pmid=16310949}}</ref>
|-
| CO<sub>2</sub> + H<sub>2</sub>O || C<sub>1</sub>-C<sub>3</sub> (I.E. C<sub>2</sub>H<sub>5</sub>OH, C<sub>2</sub>H<sub>6</sub>, etc.) || ZnO or TiO<sub>2</sub> on basic support <ref name="Reducing CO2">{{cite journal|last=Subrahmanyam|first=M.|coauthors=S. Kaneco, N. Alonso-Vante|title=A Screening for the Photo Reduction of Carbon Dioxide Supported on Metal Oxide Catalysts for C1-C3 Selectivity|journal=Applied Catalysis B: Environmental|year=1999|volume=23|pages=169–174|url=http://203.199.213.48/949/1/subrahmanyam_33.pdf|accessdate=2 June 2011|doi=10.1016/S0926-3373(99)00079-X|issue=2–3}}</ref>
|}
 
=== Gas-phase photocatalysis ===
Metal oxides excel at catalyzing gas phase reactions by photo activation, as well as thermal activation of the catalyst. Oxidation of hydrocarbons, alcohols, carbon monoxide, and ammonia have all been shown to occur when stimulated with light of greater energy than the band gap of the metal oxide.<ref name="Long photo review" /><ref name=Photometalbook /> Homophasic and heterophasic light induced oxygen isotope exchange has also been observed over TiO<sub>2</sub> and ZnO. Homophasic isotope exchange is the production of 2<sup>16</sup>O<sup>18</sup>O<sub>(g)</sub> from <sup>16</sup>O<sub>2 (g)</sub> and <sup>18</sup>O<sub>2 (g)</sub>. Heterophasic isotope exchange is the chemisorption of an oxygen isotope to the lattice of the metal oxide, and replacement of one of the oxygens in the gas phase with the lattice oxygen as shown in the following reaction.<ref name=Photometalbook />
 
<sup>18</sup>O<sub>2 (g)</sub> + <sup>16</sup>O<sub>lat</sub> → <sup>16</sup>O<sup>18</sup>O<sub>(g)</sub> + <sup>18</sup>O<sub>lat</sub>
 
==References==
{{reflist|35em}}
 
[[Category:Surface chemistry| ]]
[[Category:Transition metal oxides]]
[[Category:Transition metals]]

Revision as of 03:50, 12 January 2014

Transition metal oxides are compounds composed of oxygen atoms bound to transition metals. They are commonly utilized for their catalytic activity and semiconductive properties. Transition metal oxides are also frequently used as pigments in paints and plastics, most notably titanium dioxide. Transition metal oxides have a wide variety of surface structures which affect the surface energy of these compounds and influence their chemical properties. The relative acidity and basicity of the atoms present on the surface of metal oxides is also affected by the coordination of the metal cation and oxygen anion, which alter the catalytic properties of these compounds. For this reason, structural defects in transition metal oxides greatly influence their catalytic properties. The acidic and basic sites on the surface of metal oxides are commonly characterized via infrared spectroscopy, calorimetry among other techniques. Transition metal oxides are also able to undergo photo-assisted adsorption and desorption to control their semiconductivity. One of the more researched properties of these compounds is their response to electromagnetic radiation, which makes them useful catalysts for redox reactions, isotope exchange, specialized surfaces and a variety of other uses currently being studied.

Surface structure and stability

There is very little known about the surface structures of transition metal oxides, but their bulk crystal structures are well researched. The approach to determine the surface structure is to assume the oxides are ideal crystal, where the bulk atomic arrangement is maintained up to and including the surface plane. The surfaces will be generated by cleavages along the planes of the bulk crystal structure.[1] However, when a crystal is cleaved along a particular plane, the position of surface ions will differ from the bulk structure. Newly created surfaces will tend to minimize the surface Gibbs energy, through reconstruction, to obtain the most thermodynamically stable surface.[2] The stability of these surface structures are evaluated by surface polarity, the degree of coordinative unsaturation and defect sites.

Bulk structures

The oxide crystal structure is based on a closed-pack array of oxygen anions, with metal cations occupying interstitial sites.[1] The close-packed arrays, such as face-centered-cubic (fcc) and hexagonal-close packed (hcp), have both octahedral and tetrahedral interstices. [1]

Monoxides

The first row of transition metal monoxides (MO), TiO to NiO, have a rocksalt structure. The rock salt structure [2] is generated by filling all octahedral sites with cations in an oxygen anion fcc array.[3][4]

Dioxides

The rutile crystal structure of TiO2

The majority of transition metal dioxides (MO2) have the rutile structure, seen to the right. Materials of this stoichiometry exist for Ti, Cr, V and Mn in the first row transition metal and for Zr to Pd in the second. The rutile structure is generated by filling half of the octahedral sites with cations of the hcp oxygen anion array.[3][4]

Trioxides

Few transition metals can achieve the +6 oxidation state in an oxide, so oxides with the stoichiometry MO3 are rare.[5]

Ternary oxides

The structure of binary oxides can be predicted on the basis of the relative sizes of the metal and oxide ions and the filling of holes in a close packed oxide lattice. However, the predictions of structure are more difficult for ternary oxides. The combination of two or more metals in an oxide creates a lot of structural possibilities. Also, the stoichiometry of ternary oxide may be changed by varying the proportions of the two components and their oxidation states. For example, at least twenty ternary oxide phases are formed between strontium and vanadium including SrV2O6, Sr2V2O5, SrVO3 and Sr2VO4.[5] The structural chemistry of ternary and more complex oxides is an extensive subject, but there are a few structures that are widely adopted by ternary oxides, such as the perovskite structure.

Perovskite structure

The perovskite structure, ABO3, is the most widespread ternary phase. The perovskite structure is frequently found for ternary oxides formed with one large (A) and one small cation (B). In this structure, there is a simple cubic array of B cations, with the A cations occupying the center of the cube, and the oxide atoms are sited at the center of the 12 edges of the simple cube.[3] [3][4][5]

Surface stability

Since very little is known about the surface Gibbs energy of transition metal oxides, polarity of the surface and the degree of coordinative unsaturation of a surface cation are used to compare the stabilities of different surface structures.[2] Also, defect sites can have a huge impact on the surface stability.

Polarity of the surface

When a crystal of a binary oxide is cleaved to generate two new surfaces, each solid’s charge remains neutral. However, the structure of the two newly created surfaces may or may not be the same. If the structures are identical, the surface will be dipoleless and is considered a nonpolar surface. If the structures are different, the surface will have a strong dipole and is considered a polar surface. Examples of nonpolar surfaces include the rocksalt (100) surface, the rutile (100), (110) and (001) surfaces and the pervoskite (100) surface.[2] An example of a polar surface is the rocksalt (111) surface.[2] In general, a polar surface is less stable than a nonpolar surface because a dipole moment increases the surface Gibbs energy. Also, oxygen polar surfaces are more stable than metal polar surfaces because oxygen ions are more polarizable, which lowers the surface energy.[6]

The degree of coordinative unsaturation of a surface cation

The degree of coordinative unsaturation of a surface cation measures the number of bonds involving the cation that have to be broken to form a surface.[2] As the degree of coordinative unsaturation increases, more bonds are broken and the metal cation becomes destabilized. The destabilization of the cation increases the surface Gibbs energy, which decreases the overall stability. For example, the rutile (110) surface is more stable than the rutile (100) and (001) surfaces because it has a lower degree of coordinative unsaturation.[2]

Defect sites

NiO rock salt crystal showing cation and oxygen vacancies.

Defect sites can interfere with the stability of metal oxide surfaces, so it is important to locate and determine methods to control these sites. Oxides exhibit an abundance of point defect sites. In rocksalt surfaces, oxygen and metal cation vacancies are the most common point defects. The vacancies are produced by electron bombardment and annealing to extremely high temperatures. However, oxygen vacancies are more common and have a greater impact than metal cation vacancies. Oxygen vacancies cause reduction in between surface cations, which significantly affect the electronic energy levels.[7] Steps and kinks are two other defects that impact rocksalt surfaces. These structural defects reduce the coordination environment of the four adjacent surface cations from 5 to 4.[8] In rutile surfaces, the most common type of defect is oxygen vacancies. There are two types of oxygen vacancies, which result from either the removal of a bridging O2- ions or the removal of an inplane O2- ion. Both of these will reduce the coordination of the surface cations.[4][7][9]

Surface acidity/basicity

Extension of acid/base theories to solids

The surface of a metal oxide consists of ordered arrays of acid-base centres. The cationic metal centres act as Lewis acid sites while the anionic oxygen centres act as Lewis bases. Surface Hydroxyl groups are able to serve as Brønsted acid or base sites as they are able to give up or accept a proton.[10] The surface of most metal oxides will be, to some extent, hydroxylated under normal conditions when water vapor is present.[11] The strength and the amount of Lewis And Brønsted acid-base sites will determine the catalytic activity of many metal oxides. Due to this there is a great need to develop standard methods for the characterization of the strength, concentration, and distribution of surface acid-base sites.[10]

The concepts of Lewis acid-base theory and Brønsted-Lowry acid-base theory may be applied to surfaces, however there is no general theory that serves to determine surface acidity or basicity.[12] The qualitative treatment of Brønsted acid base theory is based on the thermodynamic equilibrium constant (Ka) of acid-base reactions between individual molecules in homogeneous systems. This treatment requires measurement of equilibrium concentrations of reactants and products. The presence of two phases also provides a problem for the quantitative acid-base determination of solids. When an acid or base is adsorbed on to an oxide surface it will perturb neighbouring acid-base sites.[13] This perturbation will inevitably influence the relaxation of the surface and make it impossible to have acid-base reactions at the surface which only involve a single surface site.

Structural relation to surface acidity/basicity

For metal oxides acidity and basicity are dependent on the charge and the radius of the metal ions as well as the character of the metal oxygen bond. The bond between oxygen and the metal is influenced by the coordination of the metal cations and the oxygen anions as well as the filling of the metal d-orbitals.[12] The surface coordination is controlled by the face that is exposed and by the surface relaxation. Structural defects can greatly contribute to the acidity or basicity as sites of high unsaturation can occur from oxygen or metal ion vacancies.

Methods of determining surface acidity/basicity

Indicator method

Adsorption of an indicator molecule was first proposed by Hammett for ordering the strength of solid acids and bases.[10] This technique is only applicable to surface Brønsted sites on metal oxides. According to Hammett, the strength of a Brønsted surface site can be determined by the Hammett acidity function,

Ho=pKBH+log[BH+][B]

where B is the basic indicator molecule. The concentration of Brønsted acid sites can be determined by titrating a suspension of the oxide with an acid/base indicator present.[10] However, this method is subject to many problems. For instance only Bronsted acid sites can be quantified with this method. Metal oxide surfaces can have both Brønsted and Lewis acid sites present at the same time which leads to a nonspecific interaction between the oxide and the indicator.[12] Also, as outlined in the theory section, the perturbation of neighboring sites upon adsorption of indicator molecules compromises the integrity of this model.[13]

IR determination of adsorbed probe molecules

The adsorption of a very weakly basic or acidic probe molecule can serve to give a picture of Brønsted and Lewis acid-base sites. Infrared spectroscopy of surface sites and adsorbed molecules can then be used to monitor the change in the vibrational frequencies upon adsorption.[10] A very weakly acidic probe molecule can be used to minimize disturbing neighboring sites so that a more accurate measure of surface acidity or basicity can be obtained. A variety of probe molecules can be used including: ammonia, pyridine, acetonitrile, carbon monoxide, and carbon dioxide.[10][12]

Calorimetric and thermal desorption

Two promising methods for the description of the acid-base properties of metal oxides are Calorimetric measurements of adsorption enthalpies and Temperature Programed desorption.[12] The measurement of the heat of adsorption of basic or acidic probe molecules can give a description of acidic and basic sites on metal oxide surfaces. Temperature programed desorption provides information about acid-base properties by saturating the surface with a probe molecule and measuring the amount that desorbs from the surface as a function of temperature. The calorimetric method provides a quantitative thermodynamic scale of acetate properties by measuring the heat of adsorption. Calorimetric methods can be considered to give a measure of the total acidity or basicity as it is not descriminate to either Lewis or Brønsted sites. However, when differential heats of adsorption are combined with other techniques, such as IR spectroscopy, the nature and distribution of acid-base adsorption sites can be obtained.[14]

Case study of surface acidity/basicity

ZrO2

representation of the zirconia surface

Zirconia exists in the monoclinic, tetragonal or cubic crystal system depending on the temperature. The surface acidity and bascity of the oxide is dependent on which phase is present and which crystal face is showing.[15] The surfaces of Zirconia have hydroxyl groups, which can act as Brønsted acids or bases, and coordination-unsaturated Zr4+O2- acid base pairs which contribute to its overall acid-base properties.[15] Adsorption studies have shown that monoclinic zirconia is more basic than tetragonal, as it forms stronger bonds with CO2. Adsorption of CO shows that the tetragonal phase has more acidic Lewis acid sites than the monoclinic phase, but that it has a lower concentration of Lewis acid sites.[15]

Photoassisted processes

Electronic band structure

The bulk electronic band structure of transition metal oxides consists of overlapping 2p orbitals from oxygen atoms, forming the lower energy, highly populated valence band, while the sparsely populated, higher energy conduction band consists of overlapping d orbitals of the transition metal cation.[16] In contrast to metals, having a continuous band of electronic states, semiconductors have a band gap that prevents the recombination of electron/hole pairs that have been separated into the conduction band/ valence band. The nanosecond scale life times of these electron/hole separations allows for charge transfer to occur with an adsorbed species on the semiconductor surface. The Potential of an acceptor must be more positive than the conduction band potential of the semiconductor in order for reduction of the species to commence. Conversely, the potential of the donor species must be more negative than that of the valence band of the semiconductor for oxidation of the species to occur.[17]

Near the surface of a semi-conducting metal oxide the valence and conduction bands are of higher energy, causing the upward bending of the band energy as shown in the band energy diagram, such that promotion of an electron from the valence band to the conduction band by light of energy greater than the band gap results in migration of the electron towards the bulk of the solid or to a counter electrode, while the hole left in the valence band moves towards the surface. The increased concentration of holes near the surface facilitates electron transfer to the solid, such as the example shown in the figure of the oxidation of redox couple D-/D.[18] In the absence of any mechanism to remove electrons from the bulk of the solid irradiation continues to excite electrons to the conduction band producing holes in the valence band. This leads to the reduction of the upward bending of the band energies near the surface, and the subsequent increase in excited electron availability for reduction reactions.[18]

This band diagram shows the excitation of an electron to the conduction band, and the reaction of a hole in the valence band with a redox couple at the surface of the solid.

The following equations are useful in describing the populations of valence and conduction bands in terms of holes and electrons for the bulk metal. n is the density of electrons in the bulk metal conduction band, and p is the density of holes in the bulk metal valence band. Ec is the lowest energy of the conduction band,Ef is the Fermi energy(electrochemical energy of the electrons), Ev is the highest energy of the valence band, Nc is the effective mass and mobility of an electron in the conduction band (constant), and Nv is the effective mass and mobility of a valence band hole (constant).[18]

n=Nce(EcEf)kT

p=Nve(EfEv)kT

Where k is Boltzmanns constant and T is the absolute temperature in Kelvin.

The use of quantum mechanics perturbation theory can aid in calculating the probability of an electronic transition taking place. The probability is proportional to the square of the amplitude of the radiation field, E0, and the square of the transition dipole moment |μif|.[17]

PEo2|μif|2

The quantum yield for an ideal system undergoing photocatatalytic events is measured as the number of events occurring per photon absorbed. The typical assumption in determining the quantum yield is that all photons are absorbed on the semiconductor surface, and the quantum yield is referred to as the apparent quantum yield. This assumption is necessary due to the difficulty in measuring the actual photons absorbed by the solid surface. The relation between the quantum yield, the rate of charge transfer, kCT, and the electron/hole recombination rate, kR, is given by the following equation.[17]

ΦkCT(kCT+kR)

Photoinduced molecular transformations at transition metal oxide surfaces can be organized in two general classes. Photoexcitation of the adsorbate which then reacts with the catalyst substrate is classified as a catalyzed photoreaction. Photoexcitation of the catalyst followed by interaction of the catalyst with a ground state reactant is classified as a sensitized photoreaction.[17]

Photoassisted adsorption and desorption

Adsorption and desorption can both be promoted by exposure of trans metal oxides to light, the predominant process being controlled by experimental conditions. Adsorption of oxygen by illumination of TiO2 or ZnO at room temperature with low pressure results in the adsorption of oxygen, while at high pressures illumination leads to photo-assisted desorption. At high temperatures the opposite effect is observed, with low pressure leading to desorption, and high pressure causing adsorption.[18][19] Kase, Yamaguchi, Suzuki, and Kaneko conducted a study of the photo-assisted chemisorption of NO on ZnO, finding that under dark conditions a negligible amount of NO adsorbed to the metal oxide, however under illumination they found that ZnO irreversibly adsorbs NO, their sample showing no desorption after irradiation had stopped.[19]

The process by which adsorption and desorption on metal oxide surfaces takes place is related to the photo generation of holes on the solid surface, which are believed to be trapped by hydroxyl groups on the surface of a transition metal oxides.[17][19] These trapped holes allow photo excited electrons to be available for chemisorption.[19] Doping of a cation of either higher or lower valence can change the electronic properties of the metal oxide.Doping with a higher valence cation typically results in an increase in n-type semi-conductivity, or raises its Fermi energy, whiledoping with a lower valence cation should lower the fermi energy level and reduce the metal oxides n-type semi-conductivity.[20] The process of doping indicates that a cation other than the transition metal cation experienced in the majority of the bulk is incorporated into the crystal structure of the semiconductor, either by replacing the cation, or interstitially adding to the matrix.[20] Doping of ZnO with Li leads to greater photo adsorption of oxygen, while doping with Ga or Al suppresses photo adsorption of oxygen. Trends in photo adsorption tend to follow trends in photo oxidative catalysis, as shown by TiO2’s and ZnO’s high degree of photo oxidative catalysis, while other transition elements like V2O5 shows no photo oxidative catalytic response as well as no photo activated adsorption of oxygen.[18]

Liquid-phase photocatalysis

One of the most exciting and most studied uses of photo catalysis is the photo-oxidation of organics as it applies to environmental decontamination.[16] In contrast to gas phase interactions with the solid surface, the vast number of variables associated with the liquid solid interface (i.e. solution pH, photocatalyst concentration, solvent effects, diffusion rate, etc.) calls for greater care to be taken to control these variables to produce consistent experimental results.[16][17] A greater variety of reactions also become possible due to the ability of solutions to stabalize charged species, making it possible to add an electron from the metal to a neutral species producing an anion that can go on to further react, or a hole to remove an electron, producing a cation that goes on to further react in solution.[18]

Oxidation

One mechanism proposed for the oxidation of adsorbed organics from solution is the production of hydroxyl radical by the valence holes migrating to the surface and reacting with adsorbed hydroxyl groups, resulting in a very strong oxidizing radical. Identification of hydroxylated oxidation intermediates and hydroxyl radicals supports this proposed mechanism, however this does not negate the possibility of the direct oxidation of the organic reactant by the valence holes because similar intermediates would be expected in either case.[17] A few of the many Photo oxidation reactions possible are shown bellow.

Starting material Photo-oxidized product Metal oxide catalyst
C2O42- + O2 + 2 H2O 2 CO2 + 2 OH- + H2O2 ZnO [18]
(CH3)2CHOH + O2 (CH3)2CO + H2O2 ZnO [18]
CH3CO2- + h+ C2H6 + CO2 Rutile TiO2 [18]
H2O H2 + 1/2O2 RuO2-TiO2-Pt [17]

Reduction

In photo reduction the promoted electron of the metal oxide is accepted by an acceptor species. In the case of CO2 reduction, shown in the table bellow, the absence of dissolved oxygen in the aqueous system favors reduction of protons to form Hydrogen radicals which then go on to reduce CO2 to HCOOH. HCOOH can then be further reduced to HCOH and water. Further reduction leads to the production of CH3 that can combine in a number of ways to produce CH4 or C2H6, etc.[21]

Starting material Reduction product Metal oxide
Cu2+ Cu0 TiO2 [18]
Pt4+ Pt0 TiO2 [18]
Cr(VI) Cr(III) TiO2 or SO42-/TiO2 [22]
CO2 + H2O C1-C3 (I.E. C2H5OH, C2H6, etc.) ZnO or TiO2 on basic support [21]

Gas-phase photocatalysis

Metal oxides excel at catalyzing gas phase reactions by photo activation, as well as thermal activation of the catalyst. Oxidation of hydrocarbons, alcohols, carbon monoxide, and ammonia have all been shown to occur when stimulated with light of greater energy than the band gap of the metal oxide.[17][18] Homophasic and heterophasic light induced oxygen isotope exchange has also been observed over TiO2 and ZnO. Homophasic isotope exchange is the production of 216O18O(g) from 16O2 (g) and 18O2 (g). Heterophasic isotope exchange is the chemisorption of an oxygen isotope to the lattice of the metal oxide, and replacement of one of the oxygens in the gas phase with the lattice oxygen as shown in the following reaction.[18]

18O2 (g) + 16Olat16O18O(g) + 18Olat

References

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  8. One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  9. One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  10. 10.0 10.1 10.2 10.3 10.4 10.5 One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  11. One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  12. 12.0 12.1 12.2 12.3 12.4 M. W. Abee, “Interaction of acid/base probe molecules with specific features on well-defined metal oxide single-crystal surfaces,” Dissertation, Blacksburg, Virginia (2001)
  13. 13.0 13.1 One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  14. One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  15. 15.0 15.1 15.2 One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  16. 16.0 16.1 16.2 One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  17. 17.0 17.1 17.2 17.3 17.4 17.5 17.6 17.7 17.8 One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  18. 18.00 18.01 18.02 18.03 18.04 18.05 18.06 18.07 18.08 18.09 18.10 18.11 18.12 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.

    My blog: http://www.primaboinca.com/view_profile.php?userid=5889534
  19. 19.0 19.1 19.2 19.3 One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  20. 20.0 20.1 One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  21. 21.0 21.1 One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  22. One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang