基于催化器小样评价测试仪对催化型颗粒捕集器CDPF小样进行活性评价，再结合柴油机台架性能测试，采用AVL （ System for emission sampling and measurement，SESAM） FT－IR傅里叶变换红外光谱仪对全尺寸CDPF进行柴油机气态污染物影响研究，综合分析不同催化剂的CDPF对柴油机排放（二次气溶胶）气态前体物的影响。结果表明，随贵金属含量的增加，CDPF小样对CO、C3 H8的起燃温度t50依次降低。相同物种起燃温度因相同比例贵金属的剂量不同而异。在高温时，催化剂中贵金属含量、价态以及混合气组分协同作用对C3 H8转换效率影响明显；在柴油机台架性能实验中，全尺寸CDPF对CO、THC具有更低的起燃温度。在适度反应温度范围内，增加Pt负载量会促进NO氧化， Pd多以氧化态PdO存在促进NO的氧化，并且PdO还原成的Pd会促进催化剂热稳定性。 NO氧化生成NO 2的过程受到NO2浓度的抑制，同时也受柴油机排气中氧浓度的影响。在Pt、Pd和Rh同在的催化剂中，Pd含量较低的CDPF对SO2的吸附量较大，但随温度升高，助剂中CeO2促进SO2脱附，使C DPF具有一定的抗硫性。%In order to researhc catalytic performance of CD PFs ( catalyzed diesel particulate filters ) lao ded differetn catalysts, CDPF samples were evaluta ed through ag s flow reactor and full-scale CDPF s tests were conductedi n diesel engine bench based on AVL-SESAM(System for emission sampling na d measurement) FT-IR.The results show that:the light-off tem perature of CO and C3 H8 decrease in turn as content of the precious metals increase.The light-off temperatures of CDPFs loaded same proportion of noble metals approximately shows linear dependence, while the difference of light-off temperature may result from different content of same proportion of noble metals.At high temperature condition, synergistic effects of content, proportion, valence state of noble metals and gaseous emission concentrations play obvious role on light-off performance of C3 H8 .In diesel engine bench test, full-scale CDPFs present lower light-off temperature of CO and THC.Within moderate inlet temperatures, increased Pt aids in oxidization of NO, which is speculated that PdO would help to oxidize NO.The existence of Pd may intensify thermal stability of the catalyst.The oxidized process of NO is inhibited by NO2 .Meanwhile O2 concentration in the diesel exhaust also affects oxidization of NO.Higher Pd content in Al2 O3 coating increase production of nitrate.With combination of Pt/Pd/Rh, the CDPF loaded lower Pd adsorbs much more SO2 on the catalysts.However, as the temperature increases, CeO2 promotes desorption of SO2 on the catalysts, which leads to the sulfur tolerance of the CDPF.
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