Oxygen Permeation Through Composite Oxide-Ion and Electronic Conductors

Author(s)

Kevin Huang, University of South Carolina - ColumbiaFollow
Michael Schroeder, University of Texas at Austin
John B. Goodenough, University of Texas at Austin

Document Type

Article

Subject Area(s)

Mechanical Engineering

Abstract

Oxygen permeation through composites consisting of four well-known oxide-ion conductors and a noble metal, Pd or Ag, is reported. The oxides were Zr_0.9Y_0.1O_1.95 (YSZ), (Bi_1.75Y_0.25O₃)_0.95(CeO₂)_0.05 (BYC5), Ce_0.8Sm_0.2O_1.9 (SSC), and La_0.8Sr_0.2Ga_0.83Mg_0.17O_2.815 (LSGM). The results show that (BYC5 + Ag) yields the highest oxygen permeation flux, but the composite deteriorates with time. The composites (SSC + Pd), (LSGM + Pd), and (YSZ + Pd) give stable, but relatively lower oxygen permeation flux in the order of (SSC + Pd) > (LSGM + Pd) > (YSZ + Pd). The composite microstructures indicate that (BYC5 + Ag) has the best percolating network for both oxide-ion and electronic pathways while (SSC + Pd) has the longest triple-phase boundary lengths with the smallest grains, which is beneficial to the surface oxygen exchange. It is shown that the microstructure of the composites, which strongly influences the competition between surface reaction and bulk diffusion, is technically as important as the oxide-ion conductivity. The activation energy appears to be related more to the morphology of the metallic phase than to that of the oxide phase. These results suggest that (SSC + Pd) is a promising composite mixed conductor for applications requiring oxygen separation.

Publication Info

Electrochemical and Solid-State Letters, Volume 2, Issue 8, 1999, pages 375-378.

Rights

©Electrochemical and Solid-State Letters 1999, The Electrochemical Society.

© The Electrochemical Society, Inc. 1999. All rights reserved. Except as provided under U.S. copyright law, this work may not be reproduced, resold, distributed, or modified without the express permission of The Electrochemical Society (ECS). The archival version of this work was published in Electrochemical and Solid State Letters.

Publisher's Version: http://dx.doi.org/10.1149/1.1390842

Huang, K., Schroeder, M., & Goodenough, J. B. (1999). Oxygen Permeation Through Composite Oxide‐Ion and Electronic Conductors. Electrochemical and Solid-State Letters, 2 (8), 375-378. http://dx.doi.org/10.1149/1.1390842