Improved catalyst for n butane oxidation to maleic anhydride

摘要

A process for the preparation of a promoted VPO catalyst wherein the catalyst comprises the mixed oxides of vanadium and phosphorus and wherein the catalyst is promoted with at least one of niobium cobalt iron zinc molybdenum or titanium said process comprising the steps of (i) preparing a VPO catalyst comprising vanadyl pyrophosphate as the major component and containing less than 5 wt% of vanadyl phosphate (ii) contacting the VPO catalyst with a solution comprising a metal source compound of at least one metal selected from the group consisting of niobium cobalt iron zinc molybdenum or titanium to form a metal impregnated VPO catalyst and (iii) drying the metal impregnated VPO catalyst to form the promoted VPO catalyst. In one embodiment a niobium promoted VPO catalyst is prepared.