CATALYST FOR PURIFYING EXHAUST GAS

摘要

PURPOSE:To obtain a ternary catalyst for an internal combustion engine high in durability. CONSTITUTION:A catalyst carrier is coated with a mixture consisting of catalytically active components prepared by supporting platinum and/or palladium on cerium oxide stabilized by rare earth metal (excepting zirconium and cerium) and zirconium and refractory inorg. oxide based on activated alumina and, thereafter, rhodium and/or rhodium and a platinum group metal are further supported on the carrier to obtain the objective catalyst for purifying exhaust gas. Since platinum and/or palladium are preliminarily supported on stabilized cerium oxide, the sintering of platinum and palladium is suppressed and catalytic activity can be kept long.