Hydrogen permeability in sintered CeO2 at high temperatures

Y. Nigara, K. Kawamura, T. Kawada, J. Mizusaki, M. Ishigame

研究成果: Article査読

18 被引用数 (Scopus)

抄録

It was found that the sintered CeO2, which was not perovskite-type but fluorite-type, permeated hydrogen under H2-H2O atmosphere at 1050-1800 K. Three tube-shaped specimens (φ 0.287 × 0.894 cm) (SP I, SP II, SP), the lengths of which were 1.40, 0.37, and 1.45 cm, were prepared. The nonexistence of micropores in specimens was confirmed by supplement of He (11.2%) + N2 to the outside of SP at 1650-1820 K. H2 (7.90%) + H2O (2.55%) + N2 was supplied to the outsides of SP I and SP II and Ar gas was allowed to flow to the inside of them. The flow rate to SP I was 21.2 cm3 min-1, and the flow to SP II was controlled so that the hydrogen concentrations measured by a gas chromatograph were of the same value. After the calculation of H2, H2O, and O2 concentrations in an equilibrium state inside and outside SP I and SP II and the elimination of mechanically leaked H2 and permeated hydrogen through the supporting materials (Pt rings, alumina tube, and disk), the atomic hydrogen permeability, JH, was determined. The hydrogen partial pressures in the outside and inside were 7.90 × 10-2 and 7.43 × 10-5 to 1.53 × 10-3 atm at 1050-1800 K. Log(JH mol h-1 cm-1) increases with rising temperature, T, while it is not proportional to 1/T. As the electronic conduction in CeO2 is considerably higher at low oxygen partial pressure, there is a possibility that CeO2 is an electron-proton mixed conductor under H2-H2O atmosphere at high temperatures.

本文言語English
ページ(範囲)2948-2953
ページ数6
ジャーナルJournal of the Electrochemical Society
146
8
DOI
出版ステータスPublished - 1999 8

ASJC Scopus subject areas

  • 電子材料、光学材料、および磁性材料
  • 再生可能エネルギー、持続可能性、環境
  • 表面、皮膜および薄膜
  • 電気化学
  • 材料化学

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