Three-way rare earth oxide catalyst

The invention is directed to a method for manufacturing a cost-reduced, durable three-way catalyst useful to oxidize hydrocarbons, carbon monoxide and reduce nitrogen oxides in exhaust gas generated by a gasoline internal combustion engine operated near the stoichiometric A/F ratio. More particularly, the catalyst is made by a process which comprises mixing particles of three oxide materials, ceria-zirconia particles impregnated with platinum and palladium, ceria-zirconia particles impregnated with only rhodium as the precious metal, and a precious metal free gamma-alumina particle. The invention is a method of manufacturing a three-way catalyst and the catalyst as well as its use for treating exhaust gas generated by a gasoline internal combustion engine. The catalyst composition comprises a mixture of particles of three different materials. More specifically, it includes a mixture of calcined ceria/zirconia particles impregnated with platinum together with palladium, other calcined ceria/zirconia particles impregnated with only rhodium precious metal, and alumina particles not impregnated with precious metal.