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A comparative study of SrCo0.8Nb0.2O3−δ and SrCo0.8Ta0.2O3−δ as low-temperature solid oxide fuel cell cathodes: effect of non-geometry factors on the oxygen reduction reaction
- Source :
- Journal of Materials Chemistry A; 12/21/2015, Vol. 3 Issue 47, p24064-24070, 7p
- Publication Year :
- 2015
-
Abstract
- The oxygen reduction reaction (ORR) activity of cathodes has to be improved to realize the low-temperature operation of solid-oxide fuel cells (SOFCs). Whilst geometric factors are conventionally accepted to influence the ORR activity of perovskite cathodes, other factors may also contribute and therefore need to be explored. Here, we substituted 20% niobium and tantalum which have similar ionic radii into strontium cobaltites to obtain the two perovskite oxides SrCo<subscript>0.8</subscript>Nb<subscript>0.2</subscript>O<subscript>3−δ</subscript> (SCN20) and SrCo<subscript>0.8</subscript>Ta<subscript>0.2</subscript>O<subscript>3−δ</subscript> (SCT20), respectively. Our study of the isostructural SCN20 and SCT20 allows geometric effects to be separated from other factors, and we observe better cathode performance of SCT20 cathode, which may be related to the lower electronegativity of Ta<superscript>5+</superscript>, thus resulting in higher oxygen surface exchange kinetics and diffusivity as compared with Nb<superscript>5+</superscript>. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 20507488
- Volume :
- 3
- Issue :
- 47
- Database :
- Complementary Index
- Journal :
- Journal of Materials Chemistry A
- Publication Type :
- Academic Journal
- Accession number :
- 111182808
- Full Text :
- https://doi.org/10.1039/c5ta07178j