Surface strontium enrichment on highly active perovskites for oxygen electrocatalysis in solid oxide fuel cells

• DOI: 10.1039/c2ee03397f
• Publication Date: 2012-01-12T10:46:11Z
• Authors: Ethan J. Crumlin; Eva Mutoro; Zhi Liu; Michael E. Grass; Michael D. Biegalski; Yueh-Lin Lee; Dane Morgan; Hans M. Christen; Hendrik Bluhm; Yang Shao-Horn
• Keywords: 02 engineering and technology; 0210 nano-technology; 7. Clean energy

Perovskite oxides have high catalytic activities for oxygen electrocatalysis competitive to platinum at elevated temperatures. However, little is known about the oxide surface chemistry that influences activity near ambient partial pressures, which hampers design of highly active catalysts many clean-energy technologies such as solid fuel cells. Using in situsynchrotron-based, pressure X-ray photoelectron spectroscopy study changes, we show coverage secondary phases on a (001)-oriented La0.8Sr0.2CoO3−δ (LSC) film becomes smaller than an LSC powder pellet In addition, strontium (Sr) perovskite structure enriches towards contrast having no detectable changes with increasing temperature. We propose ability reduce and develop Sr-enriched surfaces contributes its enhanced O2 relative powder-based electrodes.