La1-xLixMnO3钙钛矿催化剂同时消除NO和碳烟催化性能

Simultaneous removal of NO and soot over La1-xLixMnO3 perovskite catalysts

采用溶剂热法制备La1-xLixMnO3(x=0,0.05,0.15,0.25)钙钛矿型复合金属氧化物催化剂。通过XRD、FT-IR、XPS、H2-TPR和NO-TPD等手段对催化剂进行表征,在固定床微型反应器中评价催化剂同时消除NO和碳烟催化性能。结果表明,溶剂热法制备的La1-xLixMnO3催化剂具有单一的钙钛矿结构,催化剂中Mn物种以Mn3+和Mn4+的形式存在。Li+部分取代LaMnO3中La3+后,La1-xLixMnO3催化剂上Mn4+数量和氧空位增加,促进更多活性氧物种和氮氧化物的吸附与活化,提高氧化还原性能,改善催化活性。Li+取代量为0.15,即La0.85Li0.15MnO3催化剂催化活性较好,Tmax和Tig分别为463℃和327℃,NO最大转化率XNOmax为42.1%,反应温度TNOmax为383℃。

Catalysts of La1-xLixMnO3(x=0, 0.05, 0.15, 0.25) perovskite-type complex metal oxide were prepared by solvothermal method. The catalysts were characterized by XRD, FT-IR, XPS, H2-TPR and NO-TPD. The catalytic performance of the catalysts for eliminating nitric oxide(NO) and diesel particulate matter(soot) simultaneously was evaluated in a fixed micro reactor. The results showed that La1-xLixMnO3 catalysts had single perovskite structure and Mn species existed in the form of Mn3+ and Mn4+. When La3+ is partially substituted by Li+ in LaMnO3, there were more Mn4+ and oxygen vacancies in the La1-xLixMnO3 catalysts, which can promote the adsorption and activation of oxygen species and nitrogen oxides, thus increase the redox properties and improve the catalytic activity. The La0.85Li0.15MnO3 catalyst had better performance, where the doping amount of Li+ was 0.15, the temperature of the maximum combustion rate(Tmax) and the ignition temperature(Tig) was 463℃ and 327℃, respectively, the maximum conversion of NO(XONmax) was 42.1%, reaction temperature(TNOmax) was 383℃.