| 摘要 |
PROBLEM TO BE SOLVED: To clean nitrogen oxides efficiently particularly under excess oxygen environment in an exhaust gas-cleaning catalyst for cleaning hydrocarbons, carbon monoxide, and nitrogen oxides in exhaust gas exhausted by internal combustion engines such as automobiles (gasoline engine types, diesel engine types) or boilers. SOLUTION: The catalyst comprising powder of a porous carrier supporting palladium and/or rhodium and powder of a compound oxide represented by the formula (La1-x Ax )1-α BO1-δ (wherein, 0<x<1, 0<α<0.2, 0<=δ<=1, A is Ba and/or K, B represents at least one kind of elements selected from the group consisting of iron, cobalt, nickel, and manganese.) on while platinum is carried, can clean nitrogen oxides under excess oxygen environment. |
