High performance air electrode for solid oxide regenerative fuel cells fabricated by infiltration of nano-catalysts

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• 作者：Sung-il Lee ; Jeonghee Kim ; Ji-Won Son ; Jong-Ho Lee ; Byung-Kook Kim ; Hae-June Je ; Hae-Weon Lee ; Huesup Song ; Kyung Joong Yoon
• 关键词：Nano-catalyst ; Air electrode ; Solid oxide fuel cell ; Solid oxide electrolysis cell ; Solid oxide regenerative fuel cell
• 刊名：Journal of Power Sources
• 出版年：15 March, 2014
• 年：2014
• 卷：250
• 期：Complete
• 页码：15-20
• 全文大小：1008 K

文摘

A high performance air electrode fabricated by infiltration of highly active nano-catalysts into a porous scaffold is demonstrated for high-temperature solid oxide regenerative fuel cells (SORFCs). The nitrate precursor solution for Sm_0.5Sr_0.5CoO₃ (SSC) catalyst is impregnated into a porous La_0.6Sr_0.4Co_0.2Fe_0.8O₃ (LSCF)-gadolinia-doped ceria (GDC) composite backbone, and extremely fine SSC nano-particles are uniformly synthesized by in-situ crystallization at the initial stage of SORFC operation via homogeneous nucleation induced by urea decomposition. The SSC nano-catalysts are in the size range of 40-80聽nm and stable against coarsening upon the SORFC operation at 750聽掳C. The electrochemical performance is significantly improved by incorporation of SSC nano-catalysts in both power generation and hydrogen production modes. Systematic analysis on the impedance spectra reveals that the surface modification of the air electrode with nano-catalysts remarkably accelerates the chemical surface exchange reactions for both O₂ reduction and O^{2鈭?/sup> oxidation, which are the major limiting processes for SORFC performance.}