不同贵金属负载量催化型柴油机颗粒捕集器的催化性能

设计了分别涂覆15、25和35 g·ft^-3(1 ft=0.304 8 m)贵金属负载量的催化型柴油机颗粒捕集器(CDPF)样品。通过催化活性评价试验研究了不同贵金属负载量对CDPF的催化活性、抗劣化性以及选择性的影响。结果表明,随着贵金属负载量的增加,CDPF新鲜样品对CO和NO₂的活性依次降低,而对C₃H₈的活性先升高后降低。与新鲜样品相比,随着贵金属负载量的增加,CDPF老化样品对CO和NO₂的活性具有较强的抗劣化性能。涂覆中等负载量贵金属的CDPF样品对C₃H₈具有较好的活性和抗劣化性。新鲜样品对CO具有较高的选择性,老化样品对CO的转换率在低温范围时较低,而在中高温范围时较高。

Catalytic Performance of CDPF with Different Precious Metal Catalyst Loadings

Catalyzed diesel particulate filter(CDPF) samples with 15,25 and 35 g?ft-3 (1 ft = 0.304 8 m) precious metal catalyst loadings were designed to study the effects of precious metal catalyst loading on catalytic activity, degradation resistance and selectivity of CDPF by means of catalytic activity evaluation experiment. The results show that as precious metal catalyst loading increases, fresh CDPF samples present decreasing activity on CO and NO2, and show increasing first and then decreasing trend for the oxidation activity of C3H8. Compared with the fresh samples,as the precious metal catalyst loading increases, the aging CDPF samples have stronger degradation resistance performance on CO and NO2. The CDPF coated medium precious metal catalyst loading has better activity and degradation resistance performance on C3H8. Fresh CDPF samples present strong selectivity on CO,while aging CDPF samples have worse selectivity at low temperature than that at medium and high temperature.