METHOD FOR PRODUCING EXHAUST CLEANING CATALYST

摘要

PROBLEM TO BE SOLVED: To provide a method for producing an exhaust cleaning catalyst wherein fine particles of noble metal are disposed in a state of being extensively dispersed throughout a support made from a metallic compound or in a state of being extensively dispersed in controlled sites present in the support made from a metallic compound.

SOLUTION: The method for producing an exhaust cleaning catalyst is characterized by including a mixing process of mixing either one of a colloidal solution of a metallic compound selected from a colloidal solution (M1) comprising fine particles of a metallic compound and a polyalkyleneimine of a specific molecular weight with the fine particles of the metallic compound dispersed in the colloidal solution having specific particle diameters and a specific particle size distribution, and a colloidal solution (M2) comprising fine particles of the metallic compound and a polymeric dispersant other than polyalkyleneimines with the fine particles of the metallic compound dispersed therein having specific diameters and a specific particle size distribution, or a suspension of the metallic compound prepared by adjusting pH of the colloidal solution (M1) or (M2) of the metallic compound to desorb the polyalkyleneimine or the polymeric dispersant adsorbed by the fine particles of the metallic compound present in the colloidal solution (M1) or (M2), homogeneously with a colloidal solution of noble metal comprising fine particles of noble metal dispersed therein having specific particle diameters; and a heating process of subjecting the mixture prepared by the mixing process to a heat treatment.

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