Oxidation vanadium

Vanadium(IV) Oxide. Vanadium(IV) oxide (vanadium dioxide, VO2) is a blue-black solid, having a distorted mtile (Ti02) stmcture. It can be prepared from the reaction of V20 at the melting point with sulfur or carbonaceous reductants such as sugar or oxaUc acid. The dioxide slowly oxidizes in air. Vanadium dioxide dissolves in acids to give the stable (VO) " ions and in hot alkaUes to yield vanadate(IV) species, eg, (HV20 ) . 

Va.na.dlum(III) Oxide. Vanadium(III) oxide (vanadium sesquioxide, V2O2) is a black soHd, having the comndum (AI2O2) stmcture. It can be prepared by reduction of the pentoxide by hydrogen or carbon. Air oxidation proceeds slowly at ambient temperatures, but oxidation by chlorine at elevated temperatures to give VOCl and V20 is rapid. 

Va.na.dium (II) Oxide. Vanadium(II) oxide is a non stoichiometric material with a gray-black color, metallic luster, and metallic-type electrical conductivity. Metal—metal bonding increases as the oxygen content decreases, until an essentially metal phase containing dissolved oxygen is obtained (14). 

Secondary Niobium Oxide-Vanadium Oxide Batteries... 

Table 16. Specifications of secondary niobium oxide-vanadium oxide batteries...

The effects of various metal oxides and salts which promote ignition of amine-red fuming nitric acid systems were examined. Among soluble catalysts, copperQ oxide, ammonium metavanadate, sodium metavanadate, iron(III) chloride (and potassium hexacyanoferrate(II) with o-toluidine) are most effective. Of the insoluble materials, copper(II) oxide, iron(III) oxide, vanadium(V) oxide, potassium chromate, potassium dichromate, potassium hexacyanoferrate(III) and sodium pentacyanonitrosylferrate(II) were effective. 

Thermal decomposition—Thermal decomposition methods may be used to prepare metal oxide fumes. An aerosol of a precursor to the metal oxide (i.e., a substance that is readily decomposed, thermally, to yield the oxide) is first generated and then is heated by passing it through a heated tube to decompose it to the oxide. Metal formates, oxalates, and the like, which readily yield the oxides and do not produce objectionable side products, are commonly used precursors. In this program, fumes of iron oxide, vanadium oxide, and copper oxide were generated using this method. 

V205 Oxides. - Vanadium oxide species (VO ) are well known active com-... 

In addition to the foregoing, Gain 4 has prepared a large number of alkali vanadyl sulphites in which the proportions of basic oxide, vanadium dioxide, and sulphur dioxide vary considerably ... 

Oxides Vanadium monoxide VO, gray solid vanadium trioxide V2O3, black solid vanadium dioxide VO2, dark blue solid vanadium pentoxide V2O5, orange to red solid. The last is the most important oxide formed by the ignition in an of vanadium sulfide, 01 othei oxide, 01 vanadium used as a catalyzer, e.g., the reaction SO2 gas plus oxygen of air to form sulfur tnoxide. and the oxidation of naphthalene by air to form phthalie anhydride. 

The norbelladine derivative 408, which served as the starting material for the synthesis of ( )-oxocrinine (415) (Scheme 35), may be readily prepared from the reductive animation of piperonal with tyramine followed by acylation with trifluoroacetic anhydride (191,192). When the N-acylated monophenol 408 was treated with excess thallium tris(trifluoroacetate) in methylene chloride, the di-enone 412 was obtained in 19% yield (191), whereas use of the oxidant vanadium oxyfluoride in trifluoroacetic acid/trifluoroacetic anhydride afforded 412 in 88% yield (192). Base-induced N-deacylation of 412 was accompanied by spontaneous cyclization to furnish racemic oxocrinine (415). Attempts to oxidize the free amine derived from 408 led to the formation of a number of products, some of which resulted from oxidation at nitrogen. 

Casalot, A. andM. Pouchard. 1967. New nonstoichiometric phases of the silver oxide-vanadium pentoxide-vanadium dioxide system. I. Chemical and chrystallographic study. Bull. Soc. Chim. 10 3817-3820. 

Controlled vapor-phase oxidation of alkylthiazoles in the presence of molybdenum oxide, vanadium oxide or tin vanadate at temperatures of 250 to 400 °C affords the corresponding formyl derivative in moderate yields. 

Fotiev A.A., Volkov V.L., Kapustkin V.K., Oxide vanadium bronzes. Moskva Nauka 1978. 

Wang et al. (18) have studied binary and ternary mixtures of titanium oxide with zirconium oxide, vanadium oxide and iron oxide, among others. They reported that the by-products are produced in small amounts. Some mixtures are as active or more active than the iron oxide catalyst but are less selective. These researchers noted that in addition to the aforementioned reactions, reactions 3 to 5, the following reactions are significant ... 

VANADIUM DUST and FUME (ACGIH) VANAD-IUM(V) OXIDE VANADIUM PENTAOXIDE VANADIUMPENTOXID (GERMAN) VANADIUM PENTOXIDE, non-fused form (DOT) VANADIUM-PENTOXYDE (DUTCH) VANADIUM, PENTOXYDE de (FRENCH) WANADU PIECIOTLENEK (POLISH)... 

SYNS VANADIC OXIDE VANADIUM OXIDE VANADIUM TRIOXIDE... 

We have confirmed that fully oxidized vanadium can be just as active as nickel for dehydrogenation. 

It is the purpose of this paper to study which mechanism, particle-to-particle or vapor phase transport, is responsible fa- the mobility of vanadium in the FCC unit The approach used in this work is to measure the rate of vanadium transport to a basic oxide "vanadium trap" in fluid bed experiments. By varying the particle size distribution, the collision frequency can be changed and the rate of transport determined. Also, calculations of the mass transfer of a vapor species in a fluid are performed. 

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