K-Ba-Sm柴油车尾气碳烟氧化催化剂的制备与表征

采用KNO3、Ba(NO3)2、Sm(NO3)3.6H2O 3种化合物为原料,以多孔氧化铝为载体,运用涂抹法制备了用于催化柴油机尾气碳烟氧化的催化剂。用TPR对催化剂的活性进行了测量,并采用SEM和XRD对其结构进行了表征。实验结果表明,K-Ba-Sm催化剂的催化性能良好,最终能将陶瓷基片上的碳烟在低于450℃条件下完全催化氧化掉。其中以n(K)∶n(Ba)∶n(Sm)=1∶0.1∶0.1组成的催化剂效果最好,其起燃点为325℃。保持K、Ba的含量不变,随着Sm(NO3)3.6H2O物质的量的增大,其催化活性有些减弱,碳烟起燃温度升高。另外,K、Ba、Sm组成的催化剂有吸收空气中CO2的现象。

Preparation and Characterization of K-Ba-Sm Catalysts for Diesel Soot Oxidation

The catalysts of K-Ba-Sm oxide supported on porous alumina substrate were prepared by coating method.The catalysts were characterized by SEM and XRD and their catalytic activities were evaluated by soot oxidation reaction using the TPR system.The results showed that the K-Ba-Sm catalysts had good catalytic effects,the soot could be burnt out at 450 ℃.When n(K)∶n(Ba)∶n(Sm)=1∶0.1∶0.1,the catalyst had the best catalytic activity whose onset ignition temperature was 325 ℃.With the increasing of Sm(NO_(3))_(3)·6H_(2)O content,the onset ignition temperature became higher.In addition,the K-Ba-Sm catalysts were of the characteristic of absorbing CO_(2).