Catalyst for gas-phase catalytic ammoxidation reaction and method for producing catalyst for gas-phase catalytic ammoxidation reaction

A method for producing a catalyst for gas-phase catalytic ammoxidation reaction, the catalyst comprising a metal oxide and a silica carrier carrying the metal oxide, the method comprising

• a preparation step of preparing a precursor slurry comprising a starting material for the silica carrier and Mo;
• a drying step of spray drying the precursor slurry to obtain a dried particle;
• and
• a calcination step of calcining the dried particle, and
• at least one operation selected from the group consisting of the following (I), (II) and (III) is performed:
• (I) adding a fluorine compound in the preparation step and/or the drying step;
• (II) keeping a state of a calcination temperature of 695° C. or more under an inert gas atmosphere for 3 hours or more in the calcination step;
• and
• (III) by using, as a starting material for the silica carrier, a silica particle having an interaction coefficient C with water vapor of 1 or more and 10 or less, the interaction coefficient C being derived by a water vapor adsorption measurement, adding 50% by mass or more of the silica particle based on a total mass M of the starting material for the silica carrier in the preparation step, wherein the preparation step comprises a first silica particle addition step of adding at least a portion of the starting material for the silica carrier to a mixture comprising Mo, a Nb addition step of adding Nb to the mixture, and a second silica particle addition step of adding at least a portion of a balance of the starting material for the silica carrier to the mixture at the same time as the Nb addition step or after the Nb addition step, and wherein a ratio of a mass M1 of the starting material for the silica carrier to the total mass M, M1/M, in the first silica particle addition step is 0.4 to 0.7.