| 摘要 |
PROBLEM TO BE SOLVED: To enhance the heat and poisoning resistances of a catalyst containing a porous carrier, cerium oxide and a noble metal by forming a mixture of the porous carrier and cerium oxide particles and supporting the noble metal and other catalytic components on the mixture when the catalyst is produced. SOLUTION: Alumina powder 31 and cerium oxide powder 32 are slurried with a binder, purified water, and the like, and the resulting slurry is optionally milled so as to carry out mixing and to adjust the average particle diameter. A honeycomb (carrier) 33 is coated with the slurry and fired to fix the coating components. Catalytic components 34 other than alumina and cerium oxide are then impregnated and fired. The contact of cerium with a noble metal is suppressed and the objective catalyst having enhanced activity and durability of the noble metal is obtained. The catalyst efficiently removes NOx, hydrocarbons and CO from exhaust gas discharged from an internal combustion engine such as an automobile engine. |
