Production method for an exhaust gas purification catalyst

摘要

The catalyst comprises Pd-based composite oxide containing at least one element selected from rare earth metals. A method for producing the catalyst comprises adding a carboxylic acid to an aqueous nitrate solution of at least one rare earth metal and an aqueous solution of palladium nitrate, and calcining the mixture at a lower temperature than is conventionally used. Deterioration of palladium dispersion by crystallisation is thereby prevented.