La对柴油车尾气中可溶性有机物氧化催化剂CeO2-ZrO2的影响(英文)  

Influence of La on CeO_2-ZrO_2 Catalyst for Oxidation of Soluble Organic Fraction from Diesel Exhaust

作　　者：杨怡[1] 杨铮铮[2] 徐海迪[3] 徐宝强[1] 张艳华[1] 龚茂初[1] 陈耀强[1] 

机构地区：[1]四川大学化学学院,绿色化学与技术教育部重点实验室,成都610064 [2]四川大学建筑与环境学院,成都610064 [3]四川大学新能源与低碳技术研究院,成都610064

出　　处：《物理化学学报》2015年第12期2358-2365,共8页Acta Physico-Chimica Sinica

基　　金：supported by the National Natural Science Foundation of China(21173153);National High-Tech Research and Development Program of China(863)(2013AA065304)~~

摘　　要：采用共沉淀法分别制备CeO_2-ZrO_2(质量比60:40)和CeO_2-ZrO_2-La_2O_3(质量比60:30:10)催化剂.利用热重-差热分析(TG-DTA)对柴油车尾气中可溶性有机物(SOF)的催化活性进行测试.结果表明La改性的CeO_2-ZrO_2催化剂相较于CeO_2-ZrO_2催化剂表现出更好的活性,SOF的起燃温度为164℃,最大失重点温度为212℃;对CeO_2-ZrO_2来说,SOF在168℃开始转化,221℃转化最快.X射线衍射(XRD)结果表明,La的添加有效降低老化催化剂的晶粒尺寸增大速率.N_2吸附-脱附的结果说明La的添加有利于增大CeO_2-ZrO_2催化剂的比表面积;O_2-程序升温脱附(O_2-TPD)和X射线光电子能谱(XPS)结果表明La的改性有效增加化学吸附氧含量因此,CeO_2-ZrO_2-La_2O_3催化剂表现出较好的催化活性和抗老化性.CeO2-ZrO2 and CeO2-ZrO2-La203 catalysts with mass ratios of 60 ： 40 and 60 ： 30 ： 10 were prepared by co-precipitation method, respectively. The catalytic activity in oxidation of the soluble organic fraction （SOF） in diesel exhausts was studied using thermogravimetric-differential thermal analysis （TG- DTA）. The results indicate that the catalytic activity of the La-modified CeO2-ZrO2 catalyst is better than that of the CeOz-ZrO2 catalyst; the light-off temperature of SOF is 164 ℃, and the weightlessness fastest point temperature is 212 ℃, whereas for CeO2-ZrO2, these temperatures are 168 and 221 ℃, respectively. X-ray diffraction （XRD） shows that modification with La is beneficial to decrease the growth rate of the crystaUite size relative to that of CeO2-ZrO2 after high-temperature ageing, N2 adsorption-desorption results suggest that the addition of La enlarges the surface area. O2-temperature-programmed desorption （02- TPD） and X-ray photoelectron spectroscopy （XPS） show that modification with La increases the amount of chemisorbed oxygen on the CeO2-ZrO2 catalyst. The CeO2-ZrO2-La203 catalyst shows better activity and ageing resistance than the CeO2-ZrO2 catalyst.

关 键 词：CeO_2-ZrO_2 La改性CeO_2-ZrO_2 可溶性有机物 柴油车氧化催化剂 化学吸附氧 

分 类 号：O643.36[理学—物理化学]