Production of maleic anhydride using a mixed-oxide oxidation catalyst containing vanadium and pentavalent phosphorus

摘要

The process for the production of a mixed-oxide oxidation catalyst which, based on the vanadium and pentavalent phosphorus, has an atomic ratio of phosphorus to vanadium between 1.05 to 1 and 1.10 to 1. The process involves a salt of the tetravalent vanadium, dissolved in a non-oxidizing acid aqueous solution, with orthophosphoric acid. After the solution is concentrated the vanadium salt complex is precipitated by adding water. The precipitate is dried. The dried precipitate is put or formed into the desired form. The formed, dried precipitate is subjected to a heat treatment of at least 300 DEG C. A mixed-oxide oxidation catalyst is obtained.