| abstract |
Provided is a catalyst having a high activity and target product yield with regard to manufacturing an unsaturated aldehyde and/or an unsaturated carboxylic acid, and a high mechanical strength. A catalyst in which the catalyst composition satisfies a specific atomic ratio and in which, when preparing the catalyst, ammonium molybdate is used as a molybdenum component raw material, water is used as a solvent for dissolving the ammonium molybdate, bismuth nitrate is used as a bismuth component raw material, and nitric acid aqueous solution is used as a solvent for dissolving the bismuth nitrate, the catalyst being prepared using a method in which the weight of the water for dissolving the ammonium molybdate, the weight of the nitric acid aqueous solution for dissolving the bismuth nitrate, and the acid concentration of the nitric acid aqueous solution respectively satisfy a specific range. |