La1-xSrxMnO3复合氧化物制备、表征和苯完全催化氧化性能

Preparation,Characterization of La_(1-x)Sr_xMnO_3 Perovskites and Their Total Catalytic Combustion of Benzene

采用柠檬酸络合法合成了一系列La1-xSrxMnO3(x为0、0.1、0.2、0.3、0.4、0.5、0.7和0.9)复合氧化物,并将其用于苯的完全催化氧化。通过XRD、TPD、TPR等测试技术研究了Sr的加入对稀土复合氧化物结构及氧化-还原性能的影响。结果表明,对Mn钙钛石体系而言,Sr的加入未产生氧空位,只是提高了Mn离子的价态。过多Sr的掺杂既影响ABO3结构的形成,也影响Mn4+的氧化-还原性能,同时对苯的完全氧化产生了不利的影响。实验证明,Sr的加入量为x在0.2～0.3时活性最佳。

Perovskite-type oxides La1-x Srx MnO3 （x = 0, 0. 1, 0. 2, 0. 3, 0. 4, 0. 5, 0. 7 and 0. 9） were synthesized by the citric method and used for total catalytic combustion of benzene. They were characterized by means of XRD, O2-TPD and H2-TPR, and it was found that oxygen vacancy was not present in La1-xSrxMnO3 with Sr doping, and the valence of Mn was increased with Sr doping. The redox properties of La1-xSrxMnO3 have been improved by Sr doping, but the redox of Mn^4＋ would be limited by the further increase of Sr content. The La1-xSrxMnO3 oxides showed higher activity in total combustion of benzene, and La1-xSrx MnO3 oxides exhibited the best properties when x = 0. 2 -0. 3.