BaCeO_(3)修饰La_(0.6)Sr0.4Co_(0.2)Fe_(0.8)O_(3-δ)纳米结构阴极的耐铬毒化性能研究

Chromium-tolerance of BaCeO_(3) Decorated La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ) Nanostructured Cathodes

金属连接体产生的含铬蒸气使固体氧化物燃料电池(SOFC)的阴极性能发生快速衰减,是SOFC电堆的主要衰减机制之一。通过在La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)(LSCF)阴极上修饰Ba CeO_(3)(BCO)纳米颗粒,有效提高了阴极的电催化活性和在加速铬中毒条件下的运行稳定性。BCO颗粒既能抑制LSCF表面Sr偏析,又能优先与连接体表面的Cr_(2)O_(3)发生反应,在电极表面生成导电的BaCrO_(4)阻挡层,隔绝了阴极与连接体的直接接触,避免了SrCrO_(4)的生成。这两个因素的协同作用显著增强了BCO-LSCF阴极的耐铬毒化性能。

One of the key degradation mechanisms of solid oxide fuel cells(SOFC)stacks is the serious performance loss of the cathodes,owing to the attack by the gaseous Cr species generated from the Fe-Cr alloy interconnect.BaCeO_(3)(BCO)nanoparticles are decorated on La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)(LSCF)cathode,leading to an effective improvement in electrocatalytic activity and operating stability of the cathode under accelerated Cr poisoning conditions.The BCO nanoparticles not only suppressed the surface segregation of Sr,but also preferentially reacted with Cr_(2)O_(3 )on surface of the interconnect,forming a conductive BaCrO_(4) buffer layer on the electrode surface.The BaCrO_(4) layer separated LSCF and interconnect,to that the formation of SrCrO_(4) is eliminated.The synergistic effects of the two factors remarkably enhanced the chromium-tolerance of BCO-LSCF cathodes.