Study of oxygen reduction mechanism on Ag modified Sm_1.8Ce_0.2CuO₄ cathode for solid oxide fuel cell

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• 作者：Li-Ping Sun ; Hui Zhao ; Qiang Li ; Li-Hua Huo ; Jean-Paul Viricelle ; Christophe Pijolat
• 关键词：Solid oxide fuel cell ; Silver infiltration ; Composite cathode ; Electrode reaction
• 刊名：International Journal of Hydrogen Energy
• 出版年：2013
• 出版时间：25 October, 2013
• 年：2013
• 卷：38
• 期：32
• 页码：14060-14066
• 全文大小：1425 K

文摘

Different amount of metal silver particles are infiltrated into porous Sm_1.8Ce_0.2CuO₄ (SCC) scaffold to form SCC-Ag composite cathodes. The chemical stability, microstructure evolution and electrochemical performance of the composite cathode are investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and AC impedance spectroscopy respectively. The composite cathode exhibits enhanced chemical stability. The metal Ag remains un-reacted with SCC and Ce_0.9Gd_0.1O_1.95 (CGO) at 800?¡ãC for 72?h. The polarization resistance of the composite cathode decreases with the addition of metal Ag. The optimum cathode SCC-Ag05 exhibits the lowest area specific resistance (ASR, 0.43?¦¸?cm²) at 700?¡ãC in air. Investigation shows that metal Ag accelerates the charge transfer process in the composite cathode, and the rate limiting step for electrochemical oxygen reduction reaction (ORR) changes to oxygen dissociation and diffusion process.