| abstract |
[PROBLEMS] To provide a method for preparing, with ease and simplicity, a catalyst which can be used for producing methacrylic acid through the vapor phase catalytic oxidation of methacrolein or the like with a high yield and high selectivity, can maintain a stable yield of methacrylic acid over a long period of time and can respond to various reaction conditions. [MEANS FOR SOLVING PROBLEMS] A method for preparing a catalyst containing, as an active component, a salt formed by partially neutralizing a heteropoly acid having molybdenum, phosphorus, vanadium, cesium, antimony and ammonia as essential components, characterized in that a composite oxide containing the active components except antimony of the above essential active catalyst components is mixed with an antimony compound. The antimony compound may be added when a slurry is prepared. |