Method of producing maleic anhydride

Claim 1

In a method for the preparation of maleic anhydride by oxidizing a reactant consisting essentially of a saturated aliphatic hydrocarbon having 4-10 carbon atoms in the presence of a phosphorus-vanadium-oxygen-containing complex catalyst prepared by the process comprising: (a) contacting vanadium and phosphorus compounds under conditions which will provide a catalyst precursor wherein greater than 50 atom % of the vanadium is in the tetravalent state; (b) recovering the catalyst precursor; (c) forming the catalyst precursor into agglomerates; and (d) calcining the catalyst precursor agglomerations at a temperature between about 300° C. and 600° C. the improvement comprising employing, as the catalyst, the product of the improved process wherein the catalyst precursor after being formed into agglomerates is wetted with an aqueous liquid in an amount sufficient to enhance surface adhesion and then dried prior to calcining whereby attrition of the catalyst during the oxidizing of the reactant is substantially reduced.