Chapter 19. Electrochemical Charactarization and Identification of Reaction Sites in Oxide Anodes

  1. Narottam P. Bansal,
  2. Andrew Wereszczak and
  3. Edgar Lara-Curzio
  1. T. Nakamura,
  2. K. Yashiro,
  3. A. Kaimai,
  4. T. Otake,
  5. K. Sato,
  6. G. J. Park,
  7. T. Kawada and
  8. J. Mizusaki

Published Online: 26 MAR 2008

DOI: 10.1002/9780470291337.ch19

Advances in Solid Oxide Fuel Cells II: Ceramic Engineering and Science Proceedings, Volume 27, Issue 4

Advances in Solid Oxide Fuel Cells II: Ceramic Engineering and Science Proceedings, Volume 27, Issue 4

How to Cite

Nakamura, T., Yashiro, K., Kaimai, A., Otake, T., Sato, K., Park, G. J., Kawada, T. and Mizusaki, J. (2006) Electrochemical Charactarization and Identification of Reaction Sites in Oxide Anodes, in Advances in Solid Oxide Fuel Cells II: Ceramic Engineering and Science Proceedings, Volume 27, Issue 4 (eds N. P. Bansal, A. Wereszczak and E. Lara-Curzio), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470291337.ch19

Author Information

  1. Institute of Multidisciplinary Research for Advanced Materials, Tohoku University 2-1-1, Katahira, Aoba-ku, Sendai 980-8577, Japan

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2006

ISBN Information

Print ISBN: 9780470080542

Online ISBN: 9780470291337

SEARCH

Keywords:

  • polarization;
  • hydrogen;
  • electrode;
  • atmospheres;
  • hydrocarbons

Summary

Anode performance and reaction sites on LaCrO3 based oxides, SrZrO3 based oxides, and ceria based oxides were evaluated by means of AC impedance and steady state polarization measurements in H2-H2O-Ar gas mixtures. All oxide anodes tended to show poorer performance than Ni/YSZ cermet anode which is a popular anode for solid oxide fuel cells. Ceria based oxide showed relatively high performance among these oxides. Extraordinary large capacitance was observed in the LaCrO3 based oxide and ceria based oxide anodes. The measured large capacitance is considered to be a kind of chemical capacitance due to oxygen nonstoichiometry of the electrode material. It means that the electrode reaction proceeds via O2 diffusion through the electrode particles, which is mixed ionic and electronic conductor. Further semi-quantitative analysis indicated that O2 diffuses through almost all particles in the electrode layer. The reaction site of hydrogen oxidation could be either distributed on the whole surface of the electrode particles or located at the interface of the current collector and the electrode layer. They also imply that Au current collector might act as a catalyst and is not appropriate for evaluation of oxide anodes.