CATALYTIC COMPOSITION AND ITS PRODUCTION

摘要

PURPOSE:To provide a catalytic compsn. preventing grain growth of cerium oxide at high temp., not causing segregation of an additive added so as to prevent grain growth on cerium oxide grains and giving a catalyst for purification of exhaust gas preventing deterioration of its purification performance. CONSTITUTION:This catalytic compsn. is a solid soln. of cerium oxide, zirconium oxide and oxide of a rare earth metal, the atomic fraction of each of the rare earth metal and zirconium in the solid soln. is 0.1-0.3 and the total atomic fraction of them is 0.25-0.55.