Enhanced activity for catalytic oxidation of 1,2-dichloroethane over Al-substituted LaMnO3 perovskite catalysts
Enhanced activity for catalytic oxidation of 1,2-dichloroethane over Al-substituted LaMnO3 perovskite catalysts
复制标题
Al 取代的 LaMnO3 钙钛矿催化剂催化氧化 1,2-二氯乙烷的活性增强
DOI：
10.1016/j.apsusc.2014.04.012
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发表时间：
2014-07-15
影响因子：
6.7
通讯作者：
Lu, Ji-Qing
中科院分区：
文献类型：
--
作者：
Chen, Shu-Xia;Wang, Yu;Lu, Ji-Qing
采用溶胶-凝胶法制备了一系列Al掺杂的La_2，Al，MnO_3（x= 00.3）催化剂，考察了Al掺杂和热处理对催化剂结构和催化性能的影响。结果表明，Al掺杂和热处理对催化剂的活性有很大的影响，其中在700 ℃焙烧的La_（0.8）Al_（10.2）Mn_（03）催化剂的活性最高，T_（50）为295 ℃。H2程序升温还原和NH3程序升温脱附等表征结果表明，催化剂的高比表面积、高还原性和表面酸性的协同作用是催化剂活性提高的主要原因。然而，面积比反应速率的比较显示，在900 ℃下煅烧的催化剂具有比在500和700 ℃下煅烧的催化剂高得多的速率，这表明催化剂的结构性质对催化性能的影响比表面积大得多。催化剂的还原性在决定本征活性方面起主导作用，这与催化剂中引入Al诱导的高价Mn 4 -1物种的存在密切相关。(C)2014爱思唯尔有限公司版权所有。
A series of Al-substituted Lai _,AL,Mn03 (x=0 0.3) catalysts were prepared using a sol-gel method and tested for 1,2-dichloroethane oxidation in order to investigate the effects of Al-doping and thermal treatment on the catalyst structures and catalytic behaviors. It was found that both Al-doping and thermal treatment had great influence on the activities of the catalysts, and the highest activity was obtained on a La0.8A10.2Mn03 catalyst calcined at 700 C, with a T50 of 295 C. The enhanced activity could be attributed to synergetic effects of its high surface area, high reducibility and surface acidity, as evidenced by various characterizations such as H2 temperature-programmed reduction and NH3 temperature-programmed desorption. However, comparisons of the areal specific reaction rates revealed that the catalysts calcined at 900 C had much higher rates than the ones calcined at 500 and 700 C, suggesting that structural properties of the catalysts exerted much stronger influence on the catalytic performance than the surface area. It was also evidenced that the reducibility of the catalyst had a dominant role in determining the intrinsic activity, which was closely related to the presence of high valent Mn4-1 species in the catalyst as induced by the introduction of Al in the catalyst. (C) 2014 Elsevier B.V. All rights reserved.