物理化学学报 >> 2015, Vol. 31 >> Issue (12): 2358-2365.doi: 10.3866/PKU.WHXB201510135

催化和表面科学 上一篇    下一篇

La对柴油车尾气中可溶性有机物氧化催化剂CeO2-ZrO2的影响

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,*()   

  1. 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
  • 收稿日期:2015-07-31 发布日期:2015-12-04
  • 通讯作者: 徐海迪,陈耀强 E-mail:xuhaidi@scu.edu.cn;nic7501@scu.edu.cn
  • 基金资助:
    国家自然科学基金(21173153);国家高技术研究发展计划项目(863)(2013AA065304)

Influence of La on CeO2-ZrO2 Catalyst for Oxidation of Soluble Organic Fraction from Diesel Exhaust

Yi. YANG1,Zheng-Zheng. YANG2,Hai-Di. XU3,*(),Bao-Qiang. XU1,Yan-Hua. ZHANG1,Mao-Chu. GONG1,Yao-Qiang. CHEN1,*()   

  1. 1 Key Laboratory of Green Chemistry & Technology of the Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, P. R. China
    2 College of Architecture and Environment, Sichuan University, Chengdu 610064, P. R. China
    3 Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu 610064, P. R. China
  • Received:2015-07-31 Published:2015-12-04
  • Contact: Hai-Di. XU,Yao-Qiang. CHEN E-mail:xuhaidi@scu.edu.cn;nic7501@scu.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21173153);National High-Tech Research and DevelopmentProgram of China (863)(2013AA065304)

摘要:

采用共沉淀法分别制备CeO2-ZrO2(质量比60:40)和CeO2-ZrO2-La2O3(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CeO2-ZrO2催化剂相较于CeO2-ZrO2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CeO2-ZrO2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. N2吸附-脱附的结果说明La的添加有利于增大CeO2-ZrO2催化剂的比表面积; O2-程序升温脱附(O2-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, CeO2-ZrO2-La2O3催化剂表现出较好的催化活性和抗老化性.

关键词: CeO2-ZrO2, La改性CeO2-ZrO2, 可溶性有机物, 柴油车氧化催化剂, 化学吸附氧

Abstract:

CeO2-ZrO2 and CeO2-ZrO2-La2O3 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 (TGDTA). The results indicate that the catalytic activity of the La-modified CeO2-ZrO2 catalyst is better than that of the CeO2-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 crystallite 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 (O2-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-La2O3 catalyst shows better activity and ageing resistance than the CeO2-ZrO2 catalyst.

Key words: CeO2-ZrO2, La-modified CeO2-ZrO2, Soluble organic fraction, Diesel oxidation catalyst, Chemisorbed oxygen

MSC2000: 

  • O643