Preparation and use of phosphorus-vanadium- oxygen catalysts in producing maleic anhydride

Abstract From the Canadian patent

In the preparation of phosphorus-vanadiumoxygen catalyst, where vanadium and phosphorus are contacted under conditions to provide a catalyst precursor with vanadium in the tetravalent state and the pre-, cursor is formed into agglomerations and subsequently calcined at high temperatures, the improvement characterized by wetting the catalyst precursor with an aqueous liquid in an amount sufficient to enhance surface adhesion prior to calcining. The catalyst is used in preparing maleic anhydride with the enhanced surface adhesion reducing attrition during preparation of the maleic anhydride.