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. |