Method for producing catalyst precursor for producing α, β-unsaturated carboxylic acid, method for producing catalyst for producing α, β-unsaturated carboxylic acid, method for producing α, β-unsaturated carboxylic acid and α, β-unsaturation Method for producing carboxylic acid ester

摘要

Provided is a catalyst precursor for producing an α, β-unsaturated carboxylic acid, the catalyst precursor being capable of producing an α, β-unsaturated carboxylic acid at high yield. Also provided is a method for producing a catalyst precursor for producing α, β-unsaturated carboxylic acid, the precursor containing an ammonium radical and being a precursor of a catalyst used to produce an α, β-unsaturated carboxylic acid by vapor-phase catalytic oxidation of α, β-unsaturated aldehyde with molecular oxygen. The method comprises: (i) a step for preparing an aqueous slurry or solution (I) which contains a molybdenum-containing heteropolyacid; (ii) a step for adding an ammonium compound to the aqueous slurry or solution (I) to obtain a slurry (II) in which an ammonium salt of the heteropolyacid is precipitated; and (iii) a step for drying the slurry (II), in which an ammonium salt of the heteropolyacid is precipitated, to obtain the precursor, wherein an ammonium compound containing at least 30 mass% of ammonium carbamate is used as the ammonium compound in step (ii).