Acta Chimica Sinica ›› 2010, Vol. 68 ›› Issue (03): 276-282. Previous Articles     Next Articles

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非化学计量组成Ba1.03Ce0.5Zr0.4La0.1O3-α的化学稳定性和离子导电性

仇立干*,王茂元   

  1. (盐城师范学院化学化工学院 盐城 224051)
  • 收稿日期:2009-07-13 修回日期:2009-08-31 出版日期:2010-02-14 发布日期:2010-02-20
  • 通讯作者: 仇立干 E-mail:wmyqlg_64@hotmail.com

Chemical Stability and Ionic Conduction of Ba1.03Ce0.5Zr0.4La0.1O3-α with Nonstoichiometric Composition

Qiu Ligan* Wang Maoyuan   

  1. (School of Chemistry and Chemical Engineering, Yancheng Teachers University, Yancheng 224051)
  • Received:2009-07-13 Revised:2009-08-31 Online:2010-02-14 Published:2010-02-20
  • Contact: LiGan Qiu E-mail:wmyqlg_64@hotmail.com

A proton conductor Ba1.03Ce0.5Zr0.4La0.1O3-α with a nonstoichiometric composition was prepared by a high temperature solid state reaction. X-ray powder diffraction pattern (XRD) shows that the material was of a single orthorhombic phase of perovskite-type BaCeO3 and good stability in CO2 or water steam atmosphere at a high temperature. The SEM morphologies of the surface and the fracture of Ba1.03Ce0.5Zr0.4La0.1O3-α show that the material was compact after sintered at 1550 ℃ for 20 h in air. The conductivities and ionic transport numbers of the material in different gases were measured by using ac impendence spectroscopy and gas concentration cell methods in the temperature range of 500~900 ℃, respectively. The results indicate that the material was a pure proton conductor with the protonic transport number of 1 from 500 to 900 ℃ in wet hydrogen. In wet air, the oxide-ionic transport numbers were 0.688~0.170, the protonic transport numbers were 0.218~0.017, and the material was a mixed conductor of oxide-ions, protons and electronic holes. Under the fuel cell condition, the material was a mixed conductor of oxide ions, protons and electrons with the ionic transport numbers of 0.990~0.796 from 500 to 900 ℃. The conductivity and ionic transport numbers of Ba1.03Ce0.5Zr0.4La0.1O3-α were higher than those of BaCe0.5Zr0.4La0.1O3-α under the same experimental conditions.

Key words: Ba1.03Ce0.5Zr0.4La0.1O3-α, nonstoichiometry, chemical stability, ionic conduction