| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a device for cleaning diesel exhaust gas which, in a flow direction of the exhaust gas, comprises an oxidation catalyst, a diesel particulate filter having a catalytically active coating, a device for introducing a reducing agent from an external reducing agent source and a selective catalytic reduction (SCR) catalyst and in which the oxidation catalyst and the catalytically active coating of the diesel particulate filter comprises palladium and platinum. <P>SOLUTION: A ratio of palladium to platinum in an overall system is 8:1 to 1:15. In that case, a ratio of platinum: palladium in the oxidation catalyst does not exceed 6:1 and a ratio of platinum: palladium in the catalytically active coating of the diesel particulate filter does not exceed 10:1. Thereby an optimal NO/NO<SB>2</SB>ratio is achieved in the exhaust gas in front of the downstream SCR catalyst and optimal heating and HC conversion are achieved during active particulate filter regeneration. <P>COPYRIGHT: (C)2010,JPO&INPIT |
