Nitrogenase is an essential metalloenzyme that catalyzes the biological conversion of dinitrogen (N(2)) to ammonia (NH(3)). The vanadium (V)-nitrogenase is very similar to the "conventional" molybdenum (Mo)-nitrogenase, yet it holds unique properties of its own that may provide useful insights into the general mechanism of nitrogenase catalysis. So far, characterization of the vanadium iron (VF...

Recent studies of supported vanadium oxide catalysts have revealed that the vanadium oxide component is present as a twodimensional metal oxide overlayer on oxide supports (i.e., A1203, TiO2) (1-9). These surface vanadium oxide species are generally more selective and active than bulk, crystalline V205 for the partial oxidation of hydrocarbons (3, 5, 10, 11). The molecular structures of these s...

The effect of vanadium oxide as support and promoter on supported rhodium catalysts on the CO hydrogenation has been investigated at 0.15 and 4.0 MPa. Rh/V,O, reduced at 723 K has a good selectivity toward oxygenated products, especially C,-oxygenates, but has a low activity added as a promoter to catalysts consisting and stability. Vanadium oxide of rhodium supported on silica and alumina show...

Vanadium recovery of Thermal Power Plant Ash (TPPA) is an attractive process which simultaneously satisfies the pollution control standards regarding TPPA disposal and provides a valuable source of vanadium for industrial demands. In the present research work, sulfuric acid leaching route has been employed for vanadium recovery from an Iranian TPPA. Effects of acid concentration, temperature, a...

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...

Ascidians, so-called sea squirts, can accumulate high levels of vanadium in the vacuoles of signet ring cells, which are one type of ascidian blood cell and are also called vanadocytes. In addition to containing high concentrations of vanadium in the +3 oxidation state, the proton concentrations in vanadocyte vacuoles are extremely high. In order to elucidate the entire mechanism of the accumul...

Vanadium oxide (V2O5) is a material that can be fabricated as a thin film of only a few atomic layers thick during mechanical exfoliation due to the weak interlayer interactions, much like how graphene is created. During this project we looked at the band structure of both the bulk and mono-layered V2O5. We used computer software called ABINIT, which is installed on the high performance compute...

We made sensitive and accurate electrothermal atomic absorption spectrometric measurements of vanadium in small volumes of serum. The wet-digested sample was extracted into an organic solvent, with N-benzoyl-N-(o-tolyl)hydroxylamine (BTA) as the chelating reagent. After evaporating the solvent, we dissolved the residue in acetic acid, and injected a 60-microL aliquot into a graphite furnace. In...

Vanadium-based materials, such as V2O5, LiV3O8, VO2(B) and Li3V2(PO4)3 are compounds that share the characteristic of intercalation chemistry. Their layered or open frameworks allow facile ion movement through the interspaces, making them promising cathodes for LIB applications. To bypass bottlenecks occurring in the electrochemical performances of vanadium-based cathodes that derive from their...