The state of vanadium ions in VxOy/SBA-15 (2.7 wt % V) was studied with FTIR spectroscopy using CO and NO as probe molecules. Neither CO (at 85 K) nor NO (at RT) adsorb on the oxidized sample because of the coordinative saturation of V5+ ions and the covalent character of the V5+=O bond. After treatment of the sample in 50 kPa H2 at 673 K, the V5+ ions are reduced to two different types of V3+ ...

The synthesis of two novel catalytic materials based on vanadium mixed oxides has been described in present study. first material was a Vanadium-Phosphorous oxide (VPO) carbon-supported with fibrous morphology and very high surface area, stable under oxidizing conditions up to 350 °C. other is bulk VPO structure obtained after optimizing the calcination supported carbon fiber catalyst, which pr...

Rh nanoparticles (mean size 10 and 15 nm), prepared by epitaxial growth on NaCl surfaces, were covered with layers of crystalline vanadium oxide (mean thickness 1.5 and 25 nm) by reactive deposition in 10(-2) mbar O2. The 1.5 nm film was further stabilized with a coating layer of 25 nm amorphous alumina. The so-obtained Rh/vanadia films, containing vanadium in the V3+ and V2+ state, were treate...

The oxidation of methanol to formaldehyde on silica supported vanadium oxide is studied by density functional theory. For isolated vanadium oxide species silsesquioxane-type models are adopted. The first step is dissociative adsorption of methanol yielding CH3O(O=)V(O-)2 surface complexes. This makes the O=V(OCH3)3 molecule a suited model system. The rate-limiting oxidation step involves hydrog...

Mixed-addenda vanadium substituted polyoxometalate supported on anatase TiO2 crushed nano leaf was synthesized by an unusual reaction with titanium tetraisopropoxide at 100 ºC via sol–gel method under oil-bath condition. The materials characterized by XRD, TEM,  IR and UV–vis  techniques.  In  the  present  work,  efficient  oxidative  of  thiols  with  polyoxometalate-TiO2/hydrogen  peroxide  ...

Silica Vanadic Acid, SVA, (oxo-vanadium has been supported on silica) as a dual Lewis and Bronsted acid ability was prepared and efficiently catalyzed one-pot multi-component condensation of enolizable ketones or alkyl acetoacetates with aromatic aldehydes, acetonitrile and acetyl chloride. The described reaction was produced β-acetamido ketone or ester derivatives in high to excellent yields i...

mixed-addenda vanadium substituted polyoxometalate supported on anatase tio2 crushed nano leaf was synthesized by an unusual reaction with titanium tetraisopropoxide at 100 ºc via sol–gel method under oil-bath condition. the materials characterized by xrd, tem,  ir and uv–vis  techniques.  in  the  present  work,  efficient  oxidative  of  thiols  with  polyoxometalate-tio2/hydrogen  peroxide  ...

Oxo- and imido-vanadium(V) metal complexes supported by bis(phenolate)-functionalized N-heterocyclic carbene (NHC) ligands were synthesized structurally identified. In the presence of [(Ph3P)2N]Cl ([PPN]Cl), saturated NHC oxo-vanadium showed activity in coupling CO2 cyclohexene oxide (CHO) into cis-cyclohexene carbonate (cis-CHC). More importantly, complex bearing less electron-donating benzann...