CATALYST FOR PRODUCING METHACRYLIC ACID, ITS PRODUCTION, AND PRODUCTION OF METHACRYLIC ACID USING SAME CATALYST

摘要

PROBLEM TO BE SOLVED: To provide a catalyst capable of producing methacrylic acid at high production yield by gas phase contact oxidation of metacrolein, a production method of the catalyst, and a production method of methacrylic acid. SOLUTION: This catalyst for producing methacrylic acid is produced by heating a catalyst precursor containing at least molybdenum, phosphorus, and vanadium at 350-500 deg.C for 1-30 hours at least two times in the gas ventilation condition, temporarily cooling the catalyst precursor to 250 deg.C or lower between respective heating treatment, and keeping the temperature difference of the respective heating treatment within 30 deg.C.