采用铯、钾、铈(Cs、K、Ce)部分取代镧(La)制备了La1-xMxMnO3催化剂,并分析了催化剂的比表面积和晶格结构。在O2、NO+O2、NO2+O2三种不同的气体氛围下开展了碳烟、碳烟+催化剂的程序升温氧化试验,考察NOx对碳烟催化氧化活性的影响。研究结果表明,NOx的存在显著促进了碳烟的催化氧化,各特征温度降幅均在100 K左右,NO2的影响强于NO,但与无催化剂时相比,两者的差距明显缩小,这主要是由于NOx在催化剂表面可发生氧化还原循环反应。NOx存在并未影响催化剂活性的排序,Cs取代催化剂的活性依然最高,NO存在时碳烟的起燃温度、峰值温度和燃尽温度降低到618 K、667 K和706 K,NO2存在时碳烟的起燃温度、峰值温度和燃尽温度降低到592 K、657 K和679 K。初步分析了NOx存在时碳烟催化氧化的机理。
LaMnO3 was partially substituted at A site by Cs,K and Ce.The specific surface areas and crystal structures of La1-xMxMnO3 were analyzed.Temperature programmed oxidation tests of soot and soot+catalyst were made under O2、NO+O2、NO2+O2 respectively,to investigate the influence of NOx on soot catalytic oxidation.The results showed that NOx could significantly promote the catalytic oxidation of soot;all characteristic temperatures were decreased by 100 K;the influence from NO2 was larger than that from NO,and t...