Proton exchange membrane water electrolyzer (PEMWE) exhibits significant potential as a technology for hydrogen production driven by sustainable energy sources. In this study, the performance degradation characteristics of PEMWE under severe bubble accumulation condition lasting 100 h were investigated through in-situ and ex-situ characterization techniques. The results show that an increasing performance disparity with higher voltage, notably at lower temperatures, reaching a 58.2 % current density degradation rate at 50 °C and 2.0 V. Electrochemical impedance spectroscopy (EIS) analysis suggests that electrolyzer performance degradation is mainly due to increased charge transfer impedance, especially at the anode. In addition, the degraded electrolyzer exhibits a significant delay in reaching a stable current density during the abrupt voltage loading process, and its Tafel slope and electrochemically active surface area (ECSA) increased and decreased by 12.8 % and 13.5 %, respectively. Based on scanning electron microscopy (SEM) images, post-experiment analysis reveals pronounced thinning and noticeable cracks in both cathode and anode catalyst layers near the outlet, particularly on the anode side. Additionally, energy dispersive spectroscopy (EDS) mappings and transmission electron microscopy TEM) images confirm substantial Pt/C and IrO catalyst particle dissolution, migration, and agglomeration. The findings of this study contribute to enhancing understanding of the performance degradation mechanisms in PEMWE.

中文翻译：

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长时间、严重气泡积累条件下质子交换膜水电解槽降解机理的实验研究


质子交换膜水电解槽（PEMWE）作为可持续能源驱动的制氢技术展现出巨大的潜力。在本研究中，通过原位和异位表征技术研究了 PEMWE 在持续 100 小时的严重气泡积累条件下的性能退化特征。结果表明，随着电压升高，性能差异越来越大，尤其是在较低温度下，在 50 °C 和 2.0 V 下，电流密度下降率达到 58.2%。电化学阻抗谱 (EIS) 分析表明，电解槽性能下降主要是由于电压增加电荷转移阻抗，尤其是在阳极。此外，在突然的电压加载过程中，退化的电解槽在达到稳定电流密度方面表现出显着的延迟，其塔菲尔斜率和电化学活性表面积（ECSA）分别增加和减少了12.8%和13.5%。根据扫描电子显微镜 (SEM) 图像，实验后分析显示出口附近的阴极和阳极催化剂层明显变薄和明显的裂纹，特别是在阳极侧。此外，能量色散光谱（EDS）图和透射电子显微镜（TEM）图像证实了大量的 Pt/C 和 IrO 催化剂颗粒溶解、迁移和团聚。这项研究的结果有助于加深对 PEMWE 性能退化机制的理解。