Pd-Co-La-Ce汽车尾气净化催化剂

ACTIVITIES OF Pd-Co-La-Ce CATALYSTS FOR AUTOMOTIVE EMISSION CONTROL

催化剂用浸渍法制备。应用流动体系微型反应装置研究了Pd Co La Ce汽车尾气净化催化剂的活性、热稳定性,并进行了TPR、TPD表征。评价结果表明:对CO、NOX、C3H8转化Pd Co La Ce还原态催化剂的活性优于其氧化态;与Pd La Ce催化剂相比较,尽管对于C3H8的氧化Pd Co La Ce催化剂有所下降,但对CO、NOX的转化,催化剂的活性有很大提高;另外,对于CO、C3H8Pd Co La Ce催化剂还具有非常高的热稳定性,其对NOX热稳定性则需进一步研究。

Pd-Co-La-Ce and Pd-La-Ce catalysts were prepared by the method of impregnation.The catalytic activities and thermal stabilities of Pd-Co-La-Ce catalyst were investigated with flow-system microreactor.The catalytic performance of catalysts was characterized by temperature-programmed reduction(TPR) and temperature-programmed desorption (TPD) technique.It was shown that the activities of Pd-Co-La-Ce catalyst for CO、NO_x and C_3H_8 conversion in reduction state were better than those in oxidization state;Compared with Pd-La-Ce catalyst, the activities of Pd-Co-La-Ce catalyst for CO、NO_x conversion had been improved strongly,despite of the activity decline for C_3H_8 conversion;In addition,it had better thermal stability of Pd-Co-La-Ce catalyst for CO、C_3H_8 conversion,but the NO_x thermal stability need to study furthermore.