The creation of A-site cation defects within a perovskite oxide can substantially alter the structure and properties of its stoichiometric analogue. In this work, we demonstrate that by vacating 2 and 5% of Asite cations from SrNb0.1Co0.9O3-δ (SNC1.00) perovskites (Sr1-sNb0.1Co0.9O3-δ,s = 0.02 and 0.05; denoted as SNC0.98 and SNC0.95, respectively), a Jahn–Teller (JT) distortion with varying extents takes place, leading to the formation of a modified crystal lattice within a the perovskite framework. Electrical conductivity, electrochemical performance, chemical compatibility and microstructure of Sr1-sNb0.1Co0.9O3-δ as cathodes for solid oxide fuel cells were evaluated. Among SNC1.00, SNC0.98 and SNC0.95, SNC0.95 (P4/mmm symmetry (#123)) which exhibits a large JT distortion in conjunction with charge-ordering of cobalt (Co) shows the best oxygen reduction reaction (ORR) activity at low temperature while SNC0.98 (P4mm symmetry (#99)), which displays a local JT distortion, shows the poorest performance.
Published in RSC Advances, Volume 48, Issue 77, 2014, pages 40865-40872.
©RSC Advances 2014, Royal Society of Chemistry.
This article cannot be redistributed or further made available. This article was first published by the Royal Society of Chemistry and can be found at http://dx.doi.org/10.1039/c4ra06191h
Zhu, Y., Lin, Y., Shen, X., Sunarso, J., Zhou, W., Jiang, S., Su, Dong, Chen, F., & Shao, Z. (2014). Influence of Crystal Structure on the Electrochemical Performance of A-Site-Deficient Sr1-sNb0.1Co0.9O3-δ Perovskite Cathodes. RSC Advances, 4 (77), 40865 – 40872. http://dx.doi.org/10.1039/C4RA06191H