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• 作者：Shanwen Tao ; John T. S. Irvine ; Steven M. Plint
• 刊名：Journal of Physical Chemistry B
• 出版年：2006
• 出版时间：November 2, 2006
• 年：2006
• 卷：110
• 期：43
• 页码：21771 - 21776
• 全文大小：155K
• 年卷期：v.110,no.43(November 2, 2006)
• ISSN：1520-5207

文摘

Because of its widespread availability, natural gas is the most important fuel for early application of stationaryfuel cells, and furthermore, methane containing biogases are one of the most promising renewable energyalternatives; thus, it is very important to be able to efficiently utilize methane in fuel cells. Typically, externalsteam reforming is applied to allow methane utilization in high temperature fuel cells; however, direct oxidationwill provide a much better solution. Recently, we reported good electrochemical performance for an oxideanode La_0.75Sr_0.25Cr_0.5Mn_0.5O₃ (LSCM) in low moisture (3% H₂O) H₂ and CH₄ fuels without significant cokingin CH₄. Here, we investigate the catalytic activity of this oxide with respect to its ability to utilize methane.This oxide is found to exhibit fairly low reforming activity for both H₂O and CO₂ reforming but is active formethane oxidation. LSCM is found to be a full oxidation catalyst rather than a partial oxidation catalyst asCO₂ production dominates CO production even in CH₄-rich CH₄/O₂ mixtures. X-ray adsorption spectroscopywas utilized to confirm that Mn was the redox active species, clearly demonstrating that this material has theoxidation catalytic behavior that might be expected from a Mn perovskite and that the Cr ion is only presentto ensure stability under fuel atmospheres.