SOFC中干甲烷在Ni-YSZ阳极上的转化

以氧化钇稳定的氧化锆(YSZ)作电解质、Ni-YSZ为阳极,研究中/低浓度干甲烷在固体氧化物燃料电池(SOFC)中阳极的反应。改变甲烷浓度,测量不同电流密度下,阳极出口气体产生速率,得到不同电流密度下的CH_4转化率(X_(CH_4))与CO选择性(S_(CO))。根据质量平衡以及产物生成速率与不同反应速率之间的关系,分析干甲烷在阳极平行发生的化学和电化学反应,得到X_(CH_4)和S_(CO)与阳极反应的关系。结果表明,低浓度千甲烷,在电流密度小时,发生部分氧化(POM)反应;电流密度大时,在发生POM反应的同时,发生全氧化(DOM)反应。中浓度干甲烷,发生POM反应。当发生DOM反应时,随电流密度的增加,CO选择性降低,甲烷转化率增加的幅度降低。发生POM反应时,两种浓度甲烷的电化学转化速率基本相同。

The Conversion of Dry Methane over Ni-YSZ Anode of SOFC

The reactions of low and middle concentration dry methane were studied over the anode of solid oxide fuel cell(SOFC)with Ni/yttria-stabilized zirconia(YSZ)anode and YSZ electrolyte.The production rates of different gases at anode outlet were measured at different current density.The conversion of CH_4 and selectivity of CO changed with current density were obtained.Mass balance and relations of production rates with reaction rates were used to analyze the chemical and electrochemical reactions taking place in parallel,by which the relationships of and with different reactions were knew.For low concentration dry methane,partial oxidation of methane(POM)occurred at low current density,direct oxidation of methane(DOM)took place with the increasing of current density simultaneously with POM.For middle concentration methane,only POM occurred.The selectivity of CO decreased with the increasing of current density when DOM occurring.Low and middle concentration dry methane had about the same electrochemical reaction rate of POM.