| 摘要 |
PURPOSE:To prevent the reduction of catalytic activity by providing a layer coated with alumina which has a composition fixed with palladium oxide on a cerium oxide incorporating Pr on a carrier and depositing Pd or the like thereon. CONSTITUTION:A catalyst for purifying exhaust gas which has a layer coated with alumina incorporating both activated alumina such as gamma-alumina and delta-alumina deposited with Ce and cerium oxide and has both at least one of Pt and Rh, and Pd as a catalytic component is formed. In this case, in the layer coated with alumina, Pd is fixed as palladium oxide on cerium oxide incorporating Pr. Further heat resistance is enhanced without reducing the specific surface area in case of incorporating 3-5wt% Ce based on activated alumina and allowing 0.5-3.0wt% Pr based on Ce as a metallic ratio to preferably coexist. |
