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化学学报
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化学学报 ›› 2009, Vol. 67 ›› Issue (12): 1349-1354. 上一篇    下一篇

研究论文

BaCe0.5Zr0.4La0.1O3－α陶瓷的制备及其电性能

王茂元 仇立干* 左玉香

  

  1. (盐城师范学院化学化工学院 盐城 224051)

  • 投稿日期:2008-07-23 修回日期:2009-01-02 发布日期:2009-06-28
  • 通讯作者: 仇立干

Preparation and Electrical Properties of BaCe0.5Zr0.4La0.1O3－α Ceramic

Wang, Maoyuan Qiu, Ligan* Zuo, Yuxiang

  

  1. (School of Chemistry and Chemical Engineering, Yancheng Teachers University, Yancheng 224051)
  • Received:2008-07-23 Revised:2009-01-02 Published:2009-06-28
  • Contact: QIU Li-Gan

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以高温固相反应法合成了BaCe0.5Zr0.4La0.1O3－α陶瓷. 粉末XRD结果表明, 该陶瓷材料为单一钙钛矿型BaCeO3斜方晶结构, 在高温下、CO2或水蒸气气氛中具有较高的稳定性. 以陶瓷材料为固体电解质、多孔性铂为电极, 用交流阻抗谱技术测定了材料在500～900 ℃下, 不同气体气氛中的电导率; 用气体浓差电池方法测定了材料在干燥空气、湿润空气和湿润氢气气氛中的离子迁移数, 研究了材料的离子导电特性. 结果表明, 在500～900 ℃下, 干燥或湿润的气体气氛中, 随着温度升高和氧分压增大, 材料的电导率均增大. 在干燥空气中, 陶瓷材料的氧离子迁移数为0.685～0.147, 是一个氧离子与电子空穴的混合导体. 在湿润空气中, 陶瓷材料的质子迁移数为0.001～0.006, 氧离子迁移数为0.618～0.164, 是一个质子、氧离子和电子空穴的混合导体. 在湿润氢气中, 500～700 ℃温度范围内, 陶瓷材料的质子迁移数为1, 是一个纯的质子导体; 而在800～900 ℃温度范围内, 陶瓷材料的质子迁移数为0.957～0.954, 是一个质子与电子的混合导体, 质子电导占主导.

关键词: BaCe0.5Zr0.4La0.1O3－α, 阻抗谱, 气体浓差电池, 离子导电性

BaCe0.5Zr0.4La0.1O3－α ceramic was prepared by high temperature solid state reaction. X-ray powder diffraction pattern shows that the ceramic is of a single orthorhombic phase of perovskite-type BaCeO3 and good stability in CO2 or water steam atmosphere at high temperature. Using the ceramic as solid electrolyte and porous platinum as electrodes, the conductivities of the material in different gases were measured by using ac impendence spectroscopy, and the ionic transport numbers in dry air, wet air and wet hydrogen were examined by using a gas concentration cell method in the temperature range of 500～900 ℃. The results indicate that the conductivities of the material increase with increasing the temperature and the oxygen partial pressure in the dry or wet gases. The material is a mixed conductor of oxide-ions and electronic holes with the oxide-ionic transport numbers of 0.685～0.147 in dry air. In wet air, the protonic transport number is 0.001～0.006, the oxide-ionic transport number is 0.618～0.164, and the material is a mixed conductor of protons, oxide-ions and electronic holes. In wet hydrogen atmosphere, the protonic transport number is unity and the material is a pure protonic conductor from 500 to 700 ℃. But in the temperature range of 800～900 ℃, the material exhibits a mixed conduction of protons and electrons with the protonic transport numbers of 0.957～0.954.

Key words: BaCe0.5Zr0.4La0.1O3－α, impedance spectroscopy, gas concentration cell, ionic conduction