Phosphorus-vanadium-mixed oxide oxidation catalysts and processes for the preparation and use thereof.

摘要

Maleic anhydride is produced by the oxidation of a non-aromatic hydrocarbon having at least four carbon atoms in a straight chain with molecular oxygen or a molecular oxygen-containing gas in the vapor phase in the presence of a phosphorus-vanadium mixed oxide oxidation catalyst. Such catalysts are are prepared by introducing a substantially pentavalent vanadium-containing compound and a pentavalent phosphorus-containing compound into an alcohol medium capable of reducing the vanadium to a valence state less than -5 in the presence of an alcohol-modifying agent to form a phosphorus-vanadium mixed oxide catalyst precursor. The catalyst precursor is recovered, dried, formed into desired structures, and calcined at temperatures from about 250 DEG C to about 600 DEG C. The catalysts are highly effective in that they exhibit a weight weight productivity of at least 70 grams of maleic anhydride per kilogram of catalyst per hour.