The Study Of K/Sm And K/V Based Catalysts For Catalytic Oxidation Of Soot

In this study, the oxide catalysts supported on porous alumina substrate have been prepared by using coating method. The SEM, XRD, TG/DSC were used to characterize the catalysts and their catalytic activities were evaluated by soot oxidation reaction using the TPR system.The results showed that the K-Sm catalysts had a good catalytic effect. When K/Sm molar ratio was 1:1, its ignition point was 317℃. The K-Ba-Sm catalysts had a good catalytic effects, the soot could be burnt out under 450℃. When K/Ba/Sm molar ratio was 1:0.1:0.1, the catalyst had the best catalytic activity whose ignition point was 325℃. With increasing Sm(NO₃)₃ · 6H₂O content, the ignition temperature was incrased. When K/Ca/Sm molar ratio was 1:0.1:1, the catalyst had the best catalytic activity whose ignition point was 328℃. When K/Mg/Sm molar ratio was 1:0.1:1, the catalyst had the best catalytic activity whose ignition point was 347℃. When K/Sr/Sm molar ratio was 1:0.1:1, the catalyst had the best catalytic activity whose ignition point was 342℃. When K/V/Ca molar ratio was 1:0.1:1 and 6:1:0.1, the catalysts had the best catalytic activity whose ignition point was 325℃ and 345℃. The soot could be entirely burnt out by the catalysts prepared with the before-mentioned combination.By using the TPR system, the study found that the K-Ba-Sm, K-V-Sr, K-V-Ba, K-V-Ca had a CO₂ absorption characteristics.In a word, the Sm-based catalysts containing Ba, Mg, Sr and the K-V-Ca catalysts showed a good catalytic activity for carbon oxidation and had the potential application for for diesel engine emission control.