【摘要】 为为探讨SOFC中干甲烷流量对反应的影响,采用色谱在线检测阳极尾气,总结阳极尾气的变化规律,在此基础上,分析干甲烷在固体氧化物燃料电池Ni-YSZ阳极上的反应,寻找干甲烷流量与电流对电池阳极反应影响的数学关系。依据甲烷基元反应的活化能分析反应的途径,结果表明,随电流密度以及氧离子流量的增加,干甲烷与不同电流密度下的氧离子依次发生电化学反应。这些电化学反应分别是甲烷部分氧化反应生成CO、H2并产生电子,或生成CO、H2O、H2和产生电子的反应,或产生CO、H2O和产生电子的反应,或甲烷完全氧化的电化学反应。高流量甲烷只发生消耗氧离子最少的部分氧化反应,中流量甲烷发生前两个或前三个反应。依据法拉第第一定律及反应物之间的关系,确定甲烷的低、中、高流量的判定依据分别为:v(CH4)小于等于I/(4F),v(CH4)大于等于I/(4F)以及小于等于I/(2F),v(CH4)大于等于I/(2F)。更多还原

【Abstract】 In order to study the effect of dry methane flux on reactions at Ni-YSZ anode of solid oxide fuel cells(SOFC), dry methane with different fluxes was used. Mathematical relationship between dry methane flux/currents and anode reactions was investigated. The anode exhausted gases were measured by on-line chromatography and activation energy of methane elementary reaction was used to analyze the reaction pathway. The results show that when the current density and oxygen anion flux increase, the electrochemical reactions occur in sequence as follows: partial oxidation of methane which forms CO, H2 and electrons; and then CO, H2 O, H2 and electrons; the third reaction forms CO, H2 O and electrons and then complete oxidation of methane. The first two or three reactions occur for medium methane concentrations, and for high methane concentrations, only the partial oxidation reaction with the least ion consumption occurs. Based on Faraday’s first law and the relationship among the reactant species, the determination of low, medium or high methane concentrations is: v(CH4) is less than or equal to I/(4F), v(CH4) is higher than I/(4F) but lower than I/(2F), and v(CH4) is higher than I/(2F), respectively.更多还原