Catalysts for preparation of aromatic carboxylic anhydrides

Abstract From the Canadian patent

In accordance with the process of this invention, an improved catalyst for molecular oxidation of an aromatic hydrocarbon to form the corresponding aromatic carboxylic anhydrides is prepared by the steps of forming a catalyst precursor by depositing on titanium dioxide solids in the anatase form a continuous monolayer amount of at least one source of zirconium dioxide calcining, the thus-formed catalyst precursor under conditions sufficient to convert the zirconium oxide source into the oxide form, depositing upon the calcined catalyst precursor a catalytically effective amount of at least one vanadium compound which is convertible into vanadium oxide upon heating and calcining the …