Mathematical modeling of Ni/GDC and Au-Ni/GDC SOFC anodes performance under internal methane steam reforming conditions

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• 作者：S. Souentie ; M. Athanasiou ; D.K. Niakolas ; A. Katsaounis ; S.G. Neophytides ; C.G. Vayenas
• 关键词：SOFC ; Internal methane steam reforming ; Solid oxide fuel cells ; Ni/GDC anodes ; SOFC modeling
• 刊名：Journal of Catalysis
• 出版年：2013
• 出版时间：October, 2013
• 年：2013
• 卷：306
• 期：Complete
• 页码：116-128
• 全文大小：3216 K

文摘

A simple kinetic model has been developed to describe the catalytic and electrocatalytic performance of Ni/GDC and Au-Ni/GDC anodes of SOFCs operating under internal methane-steam reforming reaction conditions, at low and high steam-to-carbon ratio values. The model accounts for the surface dissociation of CH₄ to form methyl species which then react with H₂O to form CO and H₂. Under fuel cell operation conditions, two cases have been distinguished according to the observed electrochemical behavior; the high and the low steam-to-carbon ratio feed conditions. The former is characterized by electrochemical consumption of H₂ and CO, produced by internal CH₄ steam reforming, while the latter by electrochemical partial oxidation of CH₄, to form H₂ and CO, and oxidation of H₂. Interestingly, the coverage of methyl-type species of the catalyst surface, as extracted from the model and the catalytic kinetic data, was found to coincide with the methyl species coverage at the three-phase boundaries, as extracted from the electrocatalytic experiments. The model is in good agreement with experiment under both open-circuit and fuel cell operation conditions.