The preparation of highly pure vanadyl sulfate from sulfate solutions containing impurities of iron and aluminumwas investigated by solvent extraction with 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester (EHEHPA) and tri-n-butyl phosphate (TBP) as the phase modifier. The extraction and stripping conditions of vanadium (IV) and its separation from iron and aluminum were optimized. Under the...

The effect of the point of zero charge (PZC) of the support oxide (Al2O3,Nb2O5, SiO2 and ZrO2) on the molecular structure of hydrated vanadium oxide specieshas been investigated with EXAFS spectroscopy for low-loaded vanadium oxidecatalysts. It was found that the degree of clustering (i.e., the V---V coordinationnumber) and the V---V distance increase with decreasing PZC of ...

About 90 years ago, Henze discovered high levels of vanadium in the blood (coelomic) cells of an ascidian collected from the Bay of Naples. His discovery attracted the interdisciplinary attention of chemists, physiologists, and biochemists. Two decades ago, we quantified the vanadium levels in several ascidian tissues definitively using neutron-activation analysis and revealed that some species...

Density functional theory is employed to study structure and stability of small neutral vanadium oxide clusters in the gas phase. BPW91/LANL2DZ level of theory is used to obtain structures of VOy (y=1-5), V2Oy (y=2-7), V3Oy (y=4-9), and V4Oy (y=7-12) clusters. Enthalpies of growth and fragmentation reactions of the lowest energy isomers of vanadium oxide molecules are also obtained to study the...

BACKGROUND Vanadium is an important environmental and industrial pollutant. It has a status of reproductive toxicant and is reported to cross placental barrier. OBJECTIVE The current study was performed to assess the therapeutic efficacy of Tiron and its combination with selenium against vanadium induced toxicity in lactating and suckling rats. MATERIALS AND METHODS Rats were exposed to van...

The direct oxidative dehydrogenation of lactates with molecular oxygen is a "greener" alternative for producing pyruvates. Here we report a one-pot synthesis of mesoporous vanadia-titania (VTN), acting as highly efficient and recyclable catalysts for the conversion of ethyl lactate to ethyl pyruvate. These VTN materials feature high surface areas, large pore volumes, and high densities of isola...

Vanadium pentoxide is used as a catalyst and a ferrovanadium alloy ingredient in automotive steels and in jet engines and airframes. In addition, vanadium is found in fuel oils. Thus, occupational exposures to vanadium pentoxide and trioxide may occur during the cleaning of oil-fired ship boilers, and from oil-fired power station boilers. Occupational exposure to vanadium pentoxide induces gree...

Vanadium pentoxide mainly used as catalyst in sulphuric acid, maleic anhydride and ceramics industry, is a pollutant watering redistributed around the environment. Research on biological influence of vanadium pentoxide has gained major importance because it exerts toxic effects on a wide variety of biological systems. In this work we intent to evaluate the effects of vanadium pentoxide ranging ...

Titania supported vanadomolybdophosphoric acid (VMPA) catalysts with vanadium in different positions, incorporated into the molybdophosphoric acid structure by substituting for molybdenum and cation exchanged on the molybdophosphoric acid surface, were synthesized. The catalysts were characterized by XRD, FT-IR, Raman spectroscopy, TPR, XPS, and ESR techniques. The FT-IR and Raman spectral anal...

The interaction of vanadium with TiO2(110) surface was studied with metastable impact electron spectroscopy (MIES) and ultraviolet photoelectron spectroscopy (UPS) under ultrahigh vacuum (UHV) conditions. A strong interaction between vanadium and TiO2 is observed with the addition of the first vanadium layer. Adsorption and reaction of ethanol to ethylene were investigated with MIES, UPS and te...