| 摘要 |
PROBLEM TO BE SOLVED: To provide an exhaust gas cleaning catalyst which is excellent in cleaning performance of nitrogen oxides under an excess oxygen atmosphere (lean atmosphere) of exhaust gas. SOLUTION: This catalyst removes nitrogen oxides from combustion exhaust gas containing nitrogen oxides and more oxygen than a theoretical reaction amount to a coexisting unburned constituent. In this case, the catalyst is provided wherein rhodium and palladium are contained, respective one parts are combined, a content ratio of rhodium: palladium is 1 : 0.1 to 0.5, and total content of rhodium and palladium is 15 to 200 g/cf. In order to manufacture such the catalyst, rhodium and palladium powders which are supported with a catalyst support are lastly burnt containing reducing gas and/or steam at 400 deg.C or higher. |
