ACTIVATED CATALYST, BASED ON VANADIUM AND PHOSPHORUS MIXTY OXIDES, FOR OXIDATION REACTIONS AND ITS USE FOR THE PREPARATION OF MALEIC ACID ANHYDRIDE

摘要

Activated catalyst for oxidation reactions on the basis of mixed oxides of vanadium and phosphorus, characterized in that the vanadium has an average valence of less than +3.9. The activated catalyst is produced using a process wherein a mixed oxide, in which the vanadium has an average valence of +3.9 to more than +4, is activated at temperatures of 300 DEG to 500 DEG C. by passing over it a gaseous hydrocarbon component having 2 to 6 carbon atoms with the exclusion of molecular oxygen. The activated catalyst is used for the production of maleic anhydride from straight-chain C4-hydrocarbons in the gaseous phase.