Alumina-supported vanadium particles were prepared under ultrahigh vacuum (UHV) conditions and characterized with respect to their structural and CO adsorption properties. As supporting oxide, we used a thin, well-ordered alumina film grown on NiAl(110). This allows the application of scanning tunneling microscopy (STM), infrared reflection-absorption spectroscopy (IRAS), and X-ray photoelectro...

The vanadium oxide arsenate with formula K₂V₂O₂(AsO₄)₂, dipotassium divanadium(IV) dioxide diarsenate, has been synthesized by solid-state reaction in an evacuated silica ampoule. Its structure is isotypic with K₂V₂O₂(PO₄)₂. The framework is built up from corner-sharing VO₆ octa-hedra and AsO₄ tetra-hedra, creating an infinite [VAsO₈](∞) chain running along the a- and c-axis directions. The K⁺ ...

The inhibition of the activity of xanthine oxidase by vanadate was strikingly similar to vanadate inhibition of another molybdoprotein nitrate reductase. Although the main catalytic activity of both enzymes was inhibited, the partial NADH oxidase activity associated with these enzymes was stimulated several fold. It appears that the metal ion binds at multiple site in both enzymes. In the absen...

Our calculations show that the Reduction-coupled Oxo Activation (ROA) principle, which we reported at Irsee VI to play the critical role for the selective oxidation of n-butane to maleic anhydride by vanadium phosphorous oxide (VPO), also plays the critical role for the MMO activation of propane, as speculated during Irsee VI. However for MMO, this ROA principle involves Te=O and V rather than ...

A sensitive and simultaneous spectrophotometric flow injection method for the determination of vanadium(IV) and vanadium(V) is proposed. The method is based on the effect of ligands such as 2,4,6-tris(2-pyridyl)-1,3,5-triazine (TPTZ) and diphosphate on the conditional redox potential of iron(III)/iron(II) system. A four-channel flow system is assembled. In this flow system, diluted hydrochloric...

V-TiO2 photocatalyst with 0 ≤ V 20 mol% was prepared via the sol–gel method based on mixed oxide titanium–vanadium nanoparticles size and composition control. The vanadium–titanium oxo-alkoxy nanonoparticles were generated in a chemical micromixing reactor, coated glass beads liquid colloid deposition underwent to an appropriate thermal treatment forming crystallized nanocoatings. X-ray diffrac...

This study describes a new simple, sensitive and selective catalytic kinetic spectrophotometricmethod for the determination of vanadium (V). The method is based upon the catalytic effect ofvanadium (V) on the oxidation of Carminic acid by bromate in sulfuric acid media. The reaction wasfollowed spectrophotometrically by measuring the decrease in absorbance at 490 nm and thedependence of sensiti...

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...

Vanadium can be an important contaminant in groundwaters impacted by mining activities. In order to determine if microorganisms of the Geobacteraceae, the predominant dissimilatory metal reducers in many subsurface environments, were capable of reducing vanadium(V), Geobacter metallireducens was inoculated into a medium in which acetate was the electron donor and vanadium(V) was the sole electr...

With the excessive consumption of nonrenewable resources, exploration effective and durable materials is highly sought after in field sustainable energy conversion storage system. In this aspect, metal-organic frameworks (MOFs) are a new class crystalline porous organic-inorganic hybrid materials. MOFs have recently been gaining traction energy-related fields. Owing to coordination flexibility ...