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化学学报
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化学学报 ›› 2008, Vol. 66 ›› Issue (13): 1553-1558. 上一篇    下一篇

研究论文

新型氧离子导体La2Mo1.9Al0.1O9-α陶瓷的合成及电性能

曹娜平 孙林娈 孔德虎 陈 成 马桂林*   

  1. (苏州大学化学化工学院 江苏省有机合成重点实验室 苏州 215123)
  • 投稿日期:2007-11-03 修回日期:2008-01-10 发布日期:2008-07-14
  • 通讯作者: 马桂林

Synthesis and Electrical Properties of La2Mo1.9Al0.1O9-α Ceramics as a New Type of Oxide-ion Conductor

CAO, Na-Ping SUN, Lin-Luan KONG, De-Hu CHEN, Cheng MA, Gui-Lin*   

  1. (Key Laboratory of Organic Synthesis of Jiangsu Province, School of Chemistry and Chemical Engineering,
    Suzhou University, Suzhou 215123)
  • Received:2007-11-03 Revised:2008-01-10 Published:2008-07-14
  • Contact: MA, Gui-Lin

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通过高温固相法合成了La2Mo1.9Al0.1O9-α陶瓷样品. XRD测试结果表明, 该样品为一立方相结构, Al3＋离子在 Mo6＋位置的固溶摩尔浓度为5%时能完全抑制La2Mo2O9的相变. 采用交流阻抗谱、氧浓差电池、氧泵等电化学方法系统地研究了该陶瓷样品在600～1000 ℃下的离子导电特性. 结果表明, 氧浓差电池电动势的实测值与理论值吻合得很好, 离子迁移数为1, 表明该陶瓷样品在该温度下氧气气氛中为一纯离子导体; 氧浓差电池放电及氧的电化学透过(氧泵)实验结果进一步证实了该样品在氧气气氛中为一纯氧离子导体; 1000 ℃时其氧离子电导率达到了0.12 S•cm－1, 明显高于相同条件下母体及La2Mo1.9Ga0.1O9-α的氧离子电导率.

关键词: La2Mo1.9Al0.1O9-α, La2Mo2O9, 氧离子导体, 交流阻抗谱, 氧浓差电池, 氧泵

A ceramic sample of La2Mo1.9Al0.1O9-α was prepared by a high-temperature solid-state reaction. The XRD pattern shows that the sample is of a single cubic phase of La2Mo2O9, indicating that the phase transition in La2Mo2O9 is completely suppressed by doping Al3＋with 5% at Mo6＋sites. The ion conduction properties of the ceramic sample have been studied by impedance spectra, oxygen concentration cell, oxygen pump (electrochemical oxygen permeation) techniques in the temperature range of 600～1000 ℃. The observed electromotive ferces(EMFs) of the oxygen concentration cell are in good agreement with the theoretical values and the ion transport number is unity, indicating that the ceramic sample is a pure ion conductor in the oxygen atmosphere at the studied temperatures. The experimental results of the discharge of the oxygen concentration cell and electrochemical oxygen permeation (oxygen pump) confirmed that the ceramic sample was a pure oxygen-ion conductor under oxygen atmosphere. The oxygen-ion conductivity at 1000 ℃ reached 0.12 S• cm－1, obviously higher than that of La2Mo2O9-α and La2Mo1.9Ga0.1O9-α under the same conditions.

Key words: La2Mo1.9Al0.1O9-α, La2Mo2O9, oxygen-ion conductor, ac impedance spectroscopy, oxygen concentration cell, oxygen pump