Electrochemical impedance spectroscopy (EIS) is a powerful tool commonly used to study electrochemical systems. Nevertheless, its application in CO₂ electroreduction has been so far limited due to its complex reaction mechanism and environment. Although initial findings have demonstrated the viability of applying EIS analysis in CO₂ electrolyzers, the assignment of individual processes in the impedance spectra remains ambiguous. Therefore, a more detailed investigation, especially focused on its application in evaluating degradation mechanisms, is essential. In this study, a stable gas diffusion electrode (GDE) system was developed for a comprehensive EIS and distribution of relaxation time (DRT) evaluation to assess key degradation mechanisms under accelerated stress conditions such as high current density and low operating temperature. Validated by post-mortem analysis and complementary methods, we demonstrate the viability of this approach for operando monitoring of CO₂ electroreduction by assigning individual mechanistic processes in the GDE and linking them to performance degradation over time.

中文翻译：

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针对低温 CO2 电还原过程中性能下降的高级阻抗分析


电化学阻抗谱 （EIS） 是常用于研究电化学系统的强大工具。然而，由于其复杂的反应机理和环境，它在 CO₂ 电还原中的应用迄今为止一直受到限制。尽管初步研究结果表明在 CO₂ 电解槽中应用 EIS 分析是可行的，但阻抗谱中各个过程的分配仍然不明确。因此，必须进行更详细的研究，特别是关注其在评估降解机制中的应用。在本研究中，开发了一种稳定的气体扩散电极 （GDE） 系统，用于全面的 EIS 和弛豫时间分布 （DRT） 评估，以评估在高电流密度和低工作温度等加速应力条件下的关键降解机制。通过分析分析和补充方法验证，我们通过在 GDE 中分配单个机理过程并将它们与性能随时间下降联系起来，证明了这种方法对 CO₂ 电还原进行原位监测的可行性。