高等学校化学学报 ›› 2015, Vol. 36 ›› Issue (7): 1372-1377.doi: 10.7503/cjcu20150018

• 物理化学 • 上一篇    下一篇

Ce-Zr-O2上CuO分散性对CO氧化活性的影响

孔令智1, 王谦1, 徐丽2, 闫永胜2, 李华明2(), 杨向光3()   

  1. 1. 江苏大学能源与动力工程学院, 2. 能源研究院, 镇江 212013
    3. 中国科学院长春应用化学研究所, 长春 130022
  • 收稿日期:2015-01-07 出版日期:2015-07-10 发布日期:2015-06-05
  • 作者简介:联系人简介: 李华明, 男, 教授, 主要从事绿色化学方面的研究. E-mail:lhm@ujs.edu.cn;杨向光, 男, 博士, 研究员, 主要从事环境催化方面的研究. E-mail:xgyang@ciac.ac.cn
  • 基金资助:
    国家自然科学基金(批准号: 21273221)资助

Influence of CuO on Ce-Zr-O2 Dispersion on Catalytic Properties in CO Oxidation

KONG Lingzhi1, WANG Qian1, XU Li2, YAN Yongsheng2, LI Huaming2,*(), YANG Xiangguang3,*()   

  1. 1. School of Energy and Power Engineering, 2. Institute for Energy Research,Jiangsu University, Zhenjiang 212013, China
    3. Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
  • Received:2015-01-07 Online:2015-07-10 Published:2015-06-05
  • Contact: LI Huaming,YANG Xiangguang E-mail:lhm@ujs.edu.cn;xgyang@ciac.ac.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China(No.21273221)

摘要:

采用柠檬酸法制备了Ce-Zr-O2固溶体, 并负载了过渡金属和贵金属Pt, 其中, 以Cu作为活性组分, 在CO氧化反应中表现出最高的活性, CO完全转化的温度约为120 ℃, 明显高于负载1%Pt(质量分数)催化剂的活性. 掺杂少量Zr到CeO2(Ce0.8Zr0.2O2)中对Cu基催化剂有非常好的促进作用. 分别采用等体积浸渍法(IW)、 沉淀沉积法(DP)、 水热法(HT)以及柠檬酸法(CA)制备了Cu负载质量分数为20%的Cu/Ce0.8Zr0.2O2催化剂. 结果表明, 由沉淀沉积法制备的Cu/Ce0.8Zr0.2O2催化剂的活性最高, 在100 ℃时, CO可完全转化. TEM结果表明, CuO物种很好地分散在Ce0.8Zr0.2O2上. 吸附实验数据表明, Cu基催化剂上CO与O2之间较弱的竞争吸附是其活性高于Pt催化剂的主要原因. Cu基催化剂上的氧空位对促进O2的吸附具有重要作用, 也是影响CO低温氧化的重要因素之一.

关键词: 分散性, 氧化铜, Ce-Zr-O2固溶体, CO氧化活性, 氧空位

Abstract:

Ce-Zr-O2 solid solution was prepared by citric acid method and 10%M/Ce0.8Zr0.2O2 (M=Co, Mn, Cu) and 1%Pt/Ce0.8Zr0.2O2 were prepared by incipient-wetness impregnation method. It was found that Cu was the best active composition in CO oxidation over M/Ce0.8Zr0.2O2, which CO was completely converted into CO2 at ca. 120 ℃ and was more active than 1%Pt/Ce0.8Zr0.2O2. It was found that the optimum ratio of Ce to Zr was 4, Cu/Ce0.8Zr0.2O2 showed the best activity in CO oxidation. Deposition method(DP), incipient-wetness precipitation method(IW), hydro-thermal method(HT) and citric acid method(CA) were used to prepare 20%Cu/Ce0.8Zr0.2O2 catalysts. Cu/Ce0.8Zr0.2O2 prepared by deposition method showed better activity in CO oxidation, which CO was completely converted into CO2 at ca. 100 ℃. The data from H2-TPR showed that the redox of Cu/Ce0.8Zr0.2O2 was not a determining factor to control the CO oxidation. TEM results showed that the CuO was well dispersed on Ce0.8Zr0.2O2. Based on adsorption data of CO and O2, the high activity of Cu-based catalyst should be ascribed to the week competitive adsorption between CO and O2 over Cu/Ce0.8Zr0.2O2. The oxygen vacancy on Ce0.8Zr0.2O2 was a crucial factor to affect the CuO dispersion and to reduce the competitive adsorption between CO and O2.

Key words: Dispersion, CuO, Ce-Zr-O2 solid solution, Activity in CO oxidation, Oxygen vacancy

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