| 摘要 |
A pollution control catalyst for a catalytic converter in the exhaust system of an internal combustion engine, which catalyst comprises a support impregnated with (i) at least one platinum group precious metal, and with (ii) cerium base metal, or a combination of cerium and at least one other base metal, is facilely prepared by (1) impregnating a catalyst support with precursor compounds of said cerium base metal, or of said cerium base metal and of at least one other base metal, (2) activating said impregnated support, under a neutral or oxidizing atmosphere, at a temperature ranging from 120 DEG to 800 DEG C., (3) impregnating said catalyst support with precursor compounds of said at least one platinum group precious metal, together with a delayed-action organic reducing agent, inactive under cold conditions, which effects reduction of said platinum group precious metal precursor compounds, but not of any cerium or other base metal precursor compounds, under the conditions of the step (4) below, and (4) activating said impregnated catalyst, also under a neutral or oxidizing atmosphere, at a temperature ranging from 300 DEG to 800 DEG C. |
