物理化学学报 >> 2006, Vol. 22 >> Issue (01): 33-37.doi: 10.3866/PKU.WHXB20060107

研究论文 上一篇    下一篇

柠檬酸溶胶-凝胶法制备的Ce1-xZrxO2: 结构及其氧移动性

叶青; 王瑞璞; 徐柏庆   

  1. 清华大学化学系, 有机光电子与分子工程教育部重点实验室, 分子催化与定向转化研究室, 北京 100084
  • 收稿日期:2005-06-15 修回日期:2005-07-12 发布日期:2006-01-15
  • 通讯作者: 徐柏庆 E-mail:bqxu@mail.tsinghua.edu.cn

Structure and Oxygen Mobility of Ce1-xZrxO2 Prepared by Citric Acid Sol-gel Method

YE Qing; WANG Rui-pu; XU Bo-qing   

  1. Innovative Catalysis Program, Key Laboratory of Organic Optoelectronics & Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China
  • Received:2005-06-15 Revised:2005-07-12 Published:2006-01-15
  • Contact: Xu Bo-qing E-mail:bqxu@mail.tsinghua.edu.cn

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摘要： 采用 XRF、XRD、Raman、XPS、H2-TPR 以及与氩离子刻蚀相结合的XPS等表征技术对柠檬酸溶胶-凝胶法制备的Ce1-xZrxO2 (0≤x≤1)样品的结构及其氧移动性进行了研究. 结果表明, Ce1-xZrxO2 样品的晶型结构对其中氧的移动性有明显影响. 当x≤0.15 时, Ce1-xZrxO2 以立方CeO2相 Ce-Zr-O 固溶体存在, 随着Zr含量的逐渐增加, CeO2晶胞体积减小、氧空位浓度增加, 氧移动性逐渐增强; 当x＞0.15时, 形成四方ZrO2相和立方CeO2相Ce-Zr-O固溶体的混合物, 随着Zr含量的逐渐增加, 四方ZrO2相的含量增加、氧空位浓度减小, 氧移动性逐渐减弱. 因此, Ce0.852Zr0.152O2样品具有最高的氧移动性.

关键词: Ce1-xZrxO2, 溶胶-凝胶法, 氧移动性, 氧空位, CeO2基固溶体

Abstract: The structure and oxygen mobility of Ce1-xZrxO2 (0 ≤x≤ 1) samples prepared by citric acid sol-gel method were characterized by XRF, XRD, Raman, XPS, Ar+ etching-XPS and H2-TPR. The data showed that the crystalline structure of Ce1-xZrxO2 can significantly affect the oxygen mobility. When x≤0.15, the samples were found to exist as cubic Ce-Zr-O solid solutions. An increase in x resulted in a shrinking of the crystal unit volume, an increasing in the number of oxygen vacancies, and an increasing in the oxygen mobility as well. When x＞0.15, Ce1-xZrxO2 existed in a mixed phases of tetragonal and cubic Ce-Zr-O solid solutions; the percentage of tetragonal phase increased, oxygen vacancies decreased and oxygen mobility reduced with increasing x in these samples. Therefore, this present work shows that oxygen mobility in the Ce0.85Zr0.152O2 sample is the highest.

Key words: Ce1-xZrxO2, Sol-gel method, Oxygen mobility, Oxygen vacancy, CeO2-based solid solution