Oxygen reduction on strontium-doped LaMnO3 cathodes in the absence and presence of an iron–chromium alloy interconnect
Oxygen reduction on strontium-doped LaMnO3 cathodes in the absence and presence of an iron–chromium alloy interconnect
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DOI：
10.1016/j.jpowsour.2006.08.034
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发表时间：
2006-11
影响因子：
9.2
通讯作者：
Y. Zhen;Jian Li;S. Jiang
中科院分区：
文献类型：
--
作者：
Y. Zhen;Jian Li;S. Jiang
研究了固体氧化物燃料电池(SOFC)中掺锶LaMnO_3(LSM)电极在无Fe-Cr合金互连时的氧还原情况。结果表明，氧还原受表面交换反应控制，该反应包括氧在LSM电极表面的解离吸附和扩散，以及氧离子从LSM向YSZ电解质晶格的迁移。有Fe-Cr合金存在时，表面交换过程的反应级数和活化能与无Fe-Cr合金时相似。这表明，气态铬物种的存在只是通过阻止氧空位在LSM电极表面的形成而减少了表面交换反应的活性中心。另一方面，沉积在YSZ电解液表面的Cr2O3O4固体物种主要抑制氧离子向YSZ电解液的迁移，表现为氧离子向YSZ电解液迁移过程的活化能显著增加。
Oxygen reduction on a Sr-doped LaMnO3(LSM) electrode of a solid oxide fuel cell (SOFC) is investigated in the absence and the presence of a Fe–Cr alloy interconnect. The results show that oxygen reduction is controlled by a surface exchange reaction that involves dissociative adsorption and diffusion of oxygen on the LSM electrode surface, and migration of oxygen ions from the LSM to the yttria stabilized zirconia (YSZ) electrolyte lattice at the three-phase boundary (TPB). In the presence of Fe–Cr alloy, the reaction order and activation energy of the surface exchange process are similar to those in the absence of Fe–Cr alloy. This indicates that the presence of gaseous chromium species simply reduces the active sites for the surface exchange reaction by blocking oxygen vacancy formation on the LSM electrode surface. On the other hand, the Cr2O3/(Cr,Mn)3O4solid species deposited on the YSZ electrolyte surface primarily inhibits the migration of oxygen ions into the YSZ electrolyte, as indicated by a significant increase in the activation energy of the migration process of the oxygen ions into YSZ electrolyte.