We use density functional theory to examine structure− activity relationships of small vanadia clusters supported on anatase TiO2(001) and rutile TiO2(110) surfaces. A thermodynamic analysis indicates that the vanadia monomer cluster can be stabilized on the anatase TiO2(001) surface in a catalytically relevant oxygen environment. On the other hand, vanadia clusters tend to aggregate into dimer...

The selective oxidation of propylene to acrolein was investigated over a well-defined supported V2O5/Nb2O5 catalyst, containing a surface vanadia monolayer, with combined operando Raman/IR/MS, temperature programmed surface reaction (TPSR) spectroscopy and isotopically labeled reactants (O2 and C3D6). The dissociative chemisorption of propylene on the catalyst forms the surface allyl (H2CdCHCH2...

The growth, and reactivity of monolayer V2O5 films supported on TiO2(110) produced via the oxidation of vapor-deposited vanadium were studied using X-ray photoelectron spectroscopy (XPS) and temperature programmed desorption (TPD). Oxidation of vapor-deposited vanadium in 10-7 Torr of O2 at 600 K produced vanadia films that contained primarily V+3, while oxidation in 10-3 Torr at 400 K produced...

Porous silicon carbide (SiC) is of great potential as catalyst support in several industrially important reactions because of its unique thermophysical characteristics. Previously porous SiC was mostly obtained by a simple sol–gel or reactive replica technique which can only produce a material with low or medium surface area (< 50 m2 g(−1)). Here we report a new hybrid sol–gel approach to synth...

Within the Waste2Fuel project, innovative, high-performance, and cost-effective fuel production methods are developed to target “closed carbon cycle”. The catalysts supported on different metal oxides were characterized by XRD, XPS, Raman, UV-Vis, temperature-programmed techniques; then, they tested in CO2 hydrogenation at 1 bar. Moreover, V2O5 promotion was studied for Ni/Al2O3 catalyst. preci...

The catalytic properties of Al2O3-supported vanadia with a wide range of VOx surface density (1.4-34.2 V/nm) and structure were examined for the oxidative dehydrogenation of ethane and propane. UV-visible and Raman spectra showed that vanadia is dispersed predominately as isolated monovanadate species below ~2.3 V/nm. As surface densities increase, two-dimensional polyvanadates appear (2.3-7.0 ...

A series of supported V2O5/Al2O3 catalysts were synthesized by incipient wetness impregnation with vanadium isopropoxide in isopropanol solutions and subsequent calcination. The vanadium surface density was varied from 0.3 to 11.4 V atoms/nm2 spanning the sub-monolayer and above-monolayer regions. The resulting supported vanadium oxide catalysts were physically characterized with in situ Raman ...

With regard to the application in a microstructured reactor, a special VOx/Al2O3 catalyst powder (3 μm) was prepared and characterised by BET, XRD, UV/Vis DRS, and Raman spectroscopy. The higher the vanadium content, the higher the degree of polymerisation of the vanadium species on the support surface and the lower the BET surface area. Pelletised powders were tested in conventional tubular re...