| 摘要 |
PURPOSE:To obtain the titled catalyst capable of efficiently removing CO, HC and NOx in a waste gas and having high temp. durability by a method wherein an integral structure type carrier is coated by a slurry of activated alumina containing perovskite type composite oxide of Al and a rare earth element and, after baking in air, a main catalytic metal is supported thereon. CONSTITUTION:A rare earth metal (e.g; Ce) is impregnated in activated alumina and the resulting impregnated alumina is baked in a reductive atmosphere to prepare activated alumina containing perovskite type composite oxide shown by a formula. Subsequently, the resulting activated alumina is pulverized and coated, in a slurry form, on an integral structure type carrier such as a honeycomb shape or the like and, after drying, said coated carrier is baked at 500-750 deg.C in air atmosphere. Next, the resulting carrier after baking is immersed in a solution of a noble metal salt (e.g.; platinum chloride) and, after drying, is baked at about 500-750 deg.C in air atmosphere to activate the supported noble metal to prepare an objective catalyst. Further, as the activated alumina of a starting material, a tablet, a sphere or an extrusion molded product of gamma-, delta- or eta-alumina are used. |
