Method for producing phosphorus-vanadium oxide catalyst precursor, method for producing phosphorus-vanadium oxide catalyst, and method for producing maleic anhydride by vapor phase oxidation using the catalyst

摘要

In an organic solvent capable of reducing at least a portion of pentavalent vanadium to +4, phosphoric acid and pentavalent vanadium compounds are reacted using a phosphoric acid solution consisting substantially of orthophosphoric acid and having a concentration of 88 to 96% as a source of phosphoric acid. A process for producing a phosphorus-vanadium oxide catalyst precursor for producing maleic anhydride by vapor phase oxidation of a hydrocarbon having four carbon atoms, including the step of; And drying-milling said catalyst precursor.