Journal Article

PreJuSER-58178

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Screening of A-Substitution in the System A0.68Sr0.3Fe0.8Co0.2O3-Delta for SOFC Cathodes

Serra, J. M. ; Vert, V. B. ; Betz, M.FZJ* ; Haanappel, V. A. C.FZJ* ; Meulenberg, W. A.FZJ* ; Tietz, F.FZJ*

2008
Electrochemical Society Pennington, NJ

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Please use a persistent id in citations: doi:10.1149/1.2818766

Abstract: Several elements were studied as potential A-site substituents in the perovskite A(0.68)Sr(0.3)Fe(0.8)Co(0.2)O(3-delta) system. The considered elements included La, Pr, Sm, Nd, Er, Eu, Gd, Dy, and Ba. The multicomponent oxides were prepared following a complexation-polymerization-pyrolysis method. The materials were characterized by X-ray diffraction, thermal dilatometry, and electrical conductivity under different oxidant atmospheres. The obtained materials were studied as solid oxide fuel cell cathodes, preparing porous films on top anode-supported cells with a yttria-stabilized zirconia electrolyte and a CGO protective layer. The complete cell was characterized by direct current voltamperometry using air and wet H-2 as fuel, whereas the porosity of the layer was studied by gas diffusion experiments after electrochemical testing. Oxygen conduction was investigated on gastight membranes prepared for La- and Pr-based materials under flow of air and helium (sweep) in the range from 650 to 1000 degrees C. Pure perovskite structure was not obtained for the cations with the smallest ionic radii. The materials with the best electrochemical performance at 650 degrees C contained Pr, Sm, La, and Ba. The good electrochemical performance seems to be principally related to the intrinsic electrocatalytic properties of the material (perovskite or small clusters of the single oxide) because no clear correlations of the electrochemical performance and ionic conductivity, electronic conductivity, or gas diffusivity could be found. The electrochemical performance at 650 degrees C could be correlated with the catalytic activity for methane oxidation in a fixed bed reactor in the same temperature range. Finally, the catalytic promotion of a Pr- containing perovskite was evaluated by impregnation with Pd. (c) 2007 The Electrochemical Society.

Keyword(s): J

Note: Record converted from VDB: 12.11.2012

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Contributing Institute(s):

1. Brennstoffzellen (IEF-3)
2. Werkstoffsynthese und Herstellungsverfahren (IEF-1)

Research Program(s):

1. Rationelle Energieumwandlung (P12)
2. SOFC - Solid Oxide Fuel Cell (SOFC-20140602) (SOFC-20140602)

Appears in the scientific report 2008

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