Investigation of cathode catalyst layer interfaces evolution during accelerated stress tests for polymer electrolyte fuel cells
Investigation of cathode catalyst layer interfaces evolution during accelerated stress tests for polymer electrolyte fuel cells
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DOI：
10.1016/j.apcatb.2021.120810
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发表时间：
2021-10-20
影响因子：
22.1
通讯作者：
V. Zenyuk, Iryna
中科院分区：
文献类型：
--
作者：
Perego, Andrea;Avid, Arezoo;V. Zenyuk, Iryna
为了阐明聚合物电解质燃料电池（pefc）生命周期中离聚体-铂和离聚体-碳界面的演变，在化学计量和亚化学计量气体流动条件下，对具有高表面积（HSA）和耐用碳支撑的电极进行了催化剂和碳腐蚀加速应力测试（ast）。利用电化学表征和x射线光电子能谱（XPS）来评估组分的降解程度。催化剂AST结果表明，分散在微孔和介孔内且未与离聚体接触的Pt纳米颗粒是导致30k循环后电化学表面积损失（ECSA） 50%的主要原因，导致显著的极化损失，这在亚化学计量操作条件下更为明显。HSA碳的支持AST结果显示，在前100个循环中，离子严重降解，ECSA损失55%，而具有持久支持的电池在前2500个循环中表现出可以忽略不计的极化和ECSA衰减，这归因于更高的离子覆盖率，保留质子通路防止Pt脱离。
To elucidate the evolution of ionomer-Pt and ionomer-carbon interfaces during life cycle of polymer electrolyte fuel cells (PEFCs), electrodes with high surface area (HSA) and durable carbon supports underwent catalyst and carbon corrosion accelerated stress tests (ASTs) under stoichiometric and sub-stoichiometric gas flow conditions. Electrochemical characterizations, as well as X-ray photoelectron spectroscopy (XPS) were utilized to assess degree of components degradation. Catalyst AST results revealed that Pt nanoparticles dispersed within the micro- and meso-pores and not in contact with ionomer are the main contributor to the 50% electrochemical surface area (ECSA) loss observed after 30k cycles resulting in significant polarization loss, which is much more notable in the case of sub-stoichiometric operating condition. Support AST results for HSA carbon showed severe ionomer degradation and 55% ECSA loss within the first 100 cycles, while cell with durable support exhibited negligible polarization and ECSA decay during the first 2500 cycles attributed to higher ionomer coverage, preservation of proton pathways preventing Pt from detachment.