Composition for catalyst production, method for producing composition for catalyst production, and production method for producing oxide catalyst

A method for producing a composition for catalyst production which is used in the production of a catalyst for gas phase catalytic oxidation reaction or a catalyst for gas phase catalytic ammoxidation reaction, comprising:

• a mixing step of mixing a solid niobium starting material and hydrogen peroxide water to prepare a dispersion of the solid niobium starting material;
• and
• a dissolution step of dissolving the solid niobium starting material in the dispersion of the solid niobium starting material to prepare a niobium compound-containing aqueous solution, wherein
• a molar ratio (hydrogen peroxide/Nb) of a concentration of hydrogen peroxide to a Nb concentration of the niobium compound in the niobium compound-containing aqueous solution is 0.01 or more and 50 or less, and
• a temperature of the dissolution step is 40° C. or higher and 70° C. or lower.