| 摘要 |
PROBLEM TO BE SOLVED: To provide a device for the purification of diesel engine gases which provides thermally durable NO2 generation in conjunction with efficient heat-up performance for filter regeneration and low temperature HC (hydrocarbon) and CO activity.SOLUTION: A device comprises a first oxidation catalyst and a second oxidation catalyst disposed immediately following the first oxidation catalyst, substrates of the first and second oxidation catalysts are both through-flow honeycomb bodies, and the first and second oxidation catalysts both contain platinum and palladium. A total quantity of platinum and palladium in the leading, first catalyst of 30 to 250 g/ftis high relative to a total quantity of platinum and palladium in the trailing catalyst of 5 to 100 g/ft, and a ratio of Pt to Pd in the leading first catalyst is relatively low. |
