Raman, UV-Vis and X-ray photoelectron spectroscopy were combined in one experimental setup to directly study the interplay between structure and dispersion of SBA-15 supported vanadium oxide during dehydration. The fully hydrated catalyst is slightly reduced but consists mainly of V species with pseudo-octahedral V coordination strongly resembling the xerogel V2O5·1.2H2O. After dehydration a hi...

Heterogeneous catalysis plays a key role in the manufacture of essential products in key areas of agriculture and pharmaceuticals, but also in the production of polymers and numerous essential materials. Our understanding of heterogeneous catalysts is advancing rapidly, especially by using the latest characterisation methods on these relatively complex effect materials. At the heart of these ca...

To understand the structure-reactivity relationships for mixed-metal oxide catalysts, well-defined systems are required. Mixtures of vanadia and titania (TiO2) are of particular interest for application in heterogeneous catalysis, with TiO2 often acting as the support. By utilizing high-resolution scanning tunneling microscopy, we studied the interaction of vanadium (V) with the anatase TiO2(10...

Vanadium dioxide (VO(2)) undergoes a sharp metal-insulator transition (MIT) in the vicinity of room temperature and there is great interest in exploiting this effect in novel electronic and photonic devices. We have measured the work function of vanadium dioxide thin films across the phase transition using variable temperature Kelvin force microscopy (KFM). The work function is estimated to be ...

O2 reacts with propanediols via homogeneous pathways at 400-500 K. 1,2-Propanediol forms CH3CHO, HCHO, and CO2 via oxidative C--C cleavage and acetone via dehydration routes, while symmetrical 1,3-propanediol undergoes dehydration and oxidative dehydrogenation to form, almost exclusively, acrolein (ca. 90 % selectivity). The products formed and their kinetic dependence on reactant concentration...

Vanadium-modified (SiO2/MgO/MgCl2)•TiClx Ziegler-Natta catalysts were prepared through co-impregnation of water-soluble magnesium and vanadium salts under different pH values. Several key factors such as pH value of co-impregnation solution during catalyst preparation, catalyst performances including catalytic activity, ethylene/1-hexene copolymerization and hydrogen response were investigated....

A quadrupole-based mass spectrometer equipped with an electrospray ionization source was used to examine the gas-phase reactivity of various vanadium-oxide cations which mediate the oxidative dehydrogenation (ODH) of small alkenes and alkanes. For ion generation, a solution of V6O7(OMe)12 dissolved in deuterated methanol was subjected electrospray under very harsh conditions to obtain smaller v...

new forms of vanadium oxide nanoporous were fabricated using a simple chemical synthesis method. vanadium pentoxide (v2o5) nanoporous were synthesized by sodium metavanadate as precursor and ethylene glycol as surfactant. the samples were characterized by high resolution transmission electron microscopy (hrtem), field effect scanning electron microscopy (fesem) and x-ray diffraction (xrd), four...