| 摘要 |
PROBLEM TO BE SOLVED: To provide a catalyst for synthesizing unsaturated carboxylic acid, the catalyst allowing the unsaturated carboxylic acid to be synthesized from unsaturated aldehyde with high selectivity.SOLUTION: A method for producing the catalyst for synthesizing unsaturated carboxylic acid is provided, the catalyst being used when the unsaturated carboxylic acid is synthesized by vapor phase catalytic oxidation of unsaturated aldehyde with molecular oxygen. The method includes the steps of: preparing the slurry containing, at the least, a phosphorus raw material, a molybdenum raw material, an alkali metal raw material, at least one selected from the group consisting of ammonium compounds and ammonia, and water; drying the prepared slurry to prepare catalytic dried powder; and firing the prepared catalytic dried powder. The following conditions (1), (2) are satisfied. The condition (1) is that the size of primary particles of the catalytic dried powder is 70-400 nm. The condition (2) is that the size of secondary particles in the prepared slurry is 0.6-10 μm. |
