Vanadic acid anhydride

Synonyms vanadium(V) oxide vanadic acid anhydride vanadic anhydride. 

SynoTiycis Vanadium 51 Vanadic anhydride divanadium penta-ox de divenadium pantoxide vanadium oxide vanadic acid vanadic acid anhydride Vanadium oxysulfate xysulfato vanadium vanadium oxide sulfate vanadium oxosulfate oxo (sulfet (2-)-0)-vanadium Vanadic acid monosodiutn salt ... 

Synonyms Cl 77938 Vanadic acid anhydride Vanadic anhydride Vanadium dust and fume Vanadium oxide... 

Vanadin-saure, /. vanadic acid, -saurean-hydrid, n. vanadic anhydride, vanadium pentoxide, vanadium(V) oxide, V2O6. -stahl, m. vanadium steel, -stickstoff, m. vanadium nitride, -sulfat, n. vanadium sulfate, -ver-bindung, /. vanadium compoimd. 

Synonyms Vanadic anhydride divanadium pentoxide vanadium oxide vanadic acid... 

With tin vanadates, the selectivity for the formation of butadiene goes through a maximum at an atomic ratio Sn/V = 9. Below this ratio, the acidity is greater, leading to more maleic acid anhydride in the reaction products. Butadiene will adsorb more with increasing acidity and will have a greater opportunity to be oxidized. The resulting acid anhydride will desorb relatively easily from an acid catalyst. A basic catalyst will result in more combustion products. 

VANADIC ACID, AMMONIUM SALT see ANY250 VANADIC ACID, MONOSODIUM SALT see SKPOOO VANADIC ACID, POTASSIUM SALT see PLK810 VANADIC(II) ACID, TRISODIUM SALT see SIY250 VANADIC ANHYDRIDE see VDUOOO VANADIC OXIDE see VEAOOO VANADIO, PENTOSSIDO di (ITALIAN) see VDUOOO VANADIUM see VCPOOO... 

Biologically relevant vanadate esters (33-35) and a mixed vanadate-phosphate anhydride (36) Ad = adenosyl. For 33, the oxidation of activated glucose to gluconic acid (the lactone form is shown), as catalysed hy glucose-6-phosphate dehydrogenase (Glu-6PDH), is also depicted. 

Vanadic acid (H3VO4), tris (2-methylpropyl) ester. See Tri isobutyl vanadate Vanadic anhydride. See Vanadium pentoxide Vanadic oxide. See Vanadium trioxide Vanadium... 

The production of acetic acid from n-butene mixture is a vapor-phase catalytic process. The oxidation reaction occurs at approximately 270°C over a titanium vanadate catalyst. A 70% acetic acid yield has been reported. The major by-products are carbon oxides (25%) and maleic anhydride (3%) ... 

Although a variety of synthesis, compositions and reactor parameters were studied, the P-V-0 catalysts in the temperature series were synthesized in the up flow HTAD reactor using a 0.12 M solution of anunonium vanadate in water which contained the required amount of 85% phosphoric acid to result in a 1.2/1.0 P/V atom ratio. This atom ratio is normally preferred for the most selective oxidation of butane to maleic anhydride. Table I shows that the P/V atom ratios obtained for the analyzed, finished (green colored) catalysts were approximately the same as the feed composition when a series of preparations were studied between 350 C and 800°C. This was typical for all of the catalysts synthesized under a variety of conditions. 

The kinetics of the p-xylene oxidation over tin vanadate was studied by Mathur and Viswanath [206], A differential reactor was used at 320— 380°C. p-Tolualdehyde, maleic anhydride and p-toluic acid are the main... 

Sulfur trioxide is produced by the oxidation of S02. Although the oxidation of S02 is catalyzed by platinum, arsenic or halogens strongly poison the catalyst. Another suitable catalyst is sodium vanadate made from V2O5 and Na20. At an operating temperature of 400 °C, the catalyst is a liquid. The importance of SO3 is largely related to the fact that it is the anhydride of sulfuric acid,... 

Although little experimental data is available, numerous patents have been issued for the vapor phase catalytic oxidation of various other derivatives containing the benzene nucleus, as well as heterocyclic compounds Thus, fluorene (diphenyl methane) is oxidized to fluorenone with air in the presence of a catalyst containing iron vanadate or other suitable metal salt of the fifth or sixth group of the periodic system at a temperature of 360° to 400°.1,2 Maleic acid and anhydride are formed by the catalytic oxidation of compounds of the furan series, such as furan, furfural alcohol, furfural, methyl furfural, hydroxymethylfurfural, pyromucic acid or mixtures, with air over catalysts of molybdenum, vanadium, or other metals.133 Dimethyl benzaldehyde is formed by oxidizing pseudocumene with air at 550° C. in the presence of a tungsten oxide catalyst. Molybdenum, vanadium, or tantalum oxide catalysts may also be used to form aromatic aldehydes from o-, m-, or p-xylenes, mesitylene, p-cymene, or o-chlorotoluene by air oxidation. Times of contact of 0.3 to 0.4 seconds... 

In the vapor phase oxidation of benzene to maleic anhydride an active catalyst is necessary to force oxidation to rupture the ring without leading to complete destruction. Vanadium pentoxide or vanadium compounds such as tin vanadate have been successfully used for this purpose.26 In the oxidation of alkylated benzene compounds to benzaldehyde, benzoic acid, or phthalic anhydride, a milder form of catalyst is effective. The oxidation of naphthalene to naphthaquinone would also require a mild form of catalyst to prevent ring rupture caused by too severe oxidation. However, oxidation to phthalic anhydride may be realized under ordinary conditions by the use of such catalysts as have been found effective in benzene oxidation, i.e., oxides of the metals of the fifth and sixth groups of the periodic system, especially the oxides of vanadium and molybdenum. 

VANADIUM PENTOXIDE or VANADIUM, PENTOXYDE de (French) (1314-62-1) VjOj Noncombustible, but may initiate fire or explosions or enhance the combustibility or oxidation rate of materials that are noncombustible in air. A strong oxidizer accelerates the burning of combustible materials. Reacts with strong acids, calcium, chlorine trifluoride, peroxyformic acid, combustible materials, organic substances, sulfur, water. Reacts with lithium at elevated temperatures. Contact with alkalis forms water soluble vanadates. Aqueous solution is acidic incompatible with sulfuric acid, alkalis, ammonia, aliphatic amines, alkanolamines, alkylene oxides, amides, chlorine trifluoride, epichlorohydrin, nitromethane, organic anhydrides, isocyanates, peroxyformic acid, vinyl acetate. On small fires, use dry chemical powder (such as Purple-K-Powder), foam, water spray, or COj extinguishers. 

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