催化学报 ›› 2025, Vol. 79: 1-8.DOI: 10.1016/S1872-2067(25)64820-0

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膜电极原位表征技术: 解决CO2电催化还原中动态界面与稳定性挑战

吴佳宸, 刘鹏飞(), 杨化桂()   

  1. 华东理工大学材料科学与工程学院, 教育部超细材料重点实验室, 上海200237
  • 收稿日期:2025-07-02 接受日期:2025-08-01 出版日期:2025-12-18 发布日期:2025-10-27
  • 通讯作者: 刘鹏飞,杨化桂
  • 基金资助:
    国家自然科学基金(22379043);国家自然科学基金(22239001);上海市基础研究特区项目(22TQ1400100-12)

In-situ and operando characterizations in membrane electrode assemblies: Resolving dynamic interfaces and degradation pathways in CO2 electrocatalysis

Jiachen Wu, Pengfei Liu(), Huagui Yang()   

  1. Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China
  • Received:2025-07-02 Accepted:2025-08-01 Online:2025-12-18 Published:2025-10-27
  • Contact: Pengfei Liu, Huagui Yang
  • About author:Pengfei Liu is an Associate Professor and Doctoral Supervisor at the East China University of Science and Technology. He obtained his Ph.D. in Materials Science and Engineering from East China University of Science and Technology in 2018, followed by postdoctoral research within the same prestigious institution under Prof. Huagui Yang. Dr. Liu has established himself as a leading researcher in electrocatalytic materials and devices for sustainable energy. His pioneering work centers on the development of advanced electrocatalysts and membrane electrode assemblies for green hydrogen production via water electrolysis and coupled electrolysis, alongside innovative materials and devices for CO2 capture and its electrochemical conversion (CO2/CO electrolysis) to valuable chemicals. Recognized for his seminal contributions, he is a recipient of the Shanghai Oriental Talent Program (Youth) and the Shanghai Sailing Program. Dr. Liu has published over 50 first/corresponding-author peer-reviewed papers, garnering >9,000 citations with 8 ESI Highly Cited Papers, and holds 20+ patents. He serves as a Young Editorial Board Member for Carbon Energy, EcoEnergy, and Chemical Synthesis.
    Huagui Yang (East China University of Science and Technology) is an eminent scholar and National Science Fund for Distinguished Young Scholars recipient, renowned for his pioneering contributions to functional materials for solar energy conversion. He earned his Ph.D. from the National University of Singapore in Chemical and Biomolecular Engineering in 2005, followed by postdoctoral research at the University of Queensland, Australia (2007‒2008). Since 2008, he has excelled as a Professor at East China University of Science and Technology, leading groundbreaking research in photo(electro)catalysis and electrocatalysis for hydrogen production and CO2 utilization, with seminal work on atomic-level material design and high-performance catalytic systems. His illustrious achievements include publishing over 300 papers in top-tier journals like Nature and Science, receiving the State Council Special Allowance. Continuously honored in Elsevier’s Highly Cited Chinese Researchers, his innovative research drives global advancements in clean energy technologies.
  • Supported by:
    National Natural Science Foundation of China(22379043);National Natural Science Foundation of China(22239001);Shanghai Pilot Program for Basic Research Science and Technology Commission of Shanghai Municipality(22TQ1400100-12)

摘要:

电催化二氧化碳还原(CO2RR)技术通过将CO2转化为高附加值化学品, 为碳中和目标提供了关键路径. 膜电极组件(MEA)因具备低欧姆电阻、高电流密度运行能力及模块化放大潜力, 已成为工业级CO2电还原的核心器件结构. 然而, MEA在实际运行中面临膜-电极界面动态演化的复杂性: 催化剂在工业级电流密度(>500 mA cm-2)下的结构重构与溶解(如Cu+物种的动态稳定性)、电解质/气体扩散电极(GDE)界面因碳酸盐沉淀引发的堵塞与水淹, 以及局域微环境极端pH梯度对反应路径的调控——这些动态过程难以通过传统三电极体系或非原位表征解析, 亟需发展面向工况膜电极的原位表征技术.
本文聚焦同步辐射X射线技术、原位拉曼光谱及嵌入式电化学诊断等先进原位表征技术在揭示MEA动态界面机制中的突破性作用, 包括膜电极内原子尺度催化剂演化、离子/水传质动力学及界面反应微环境等. 在原子尺度催化剂演化方面, 同步辐射X射线吸收谱(XAS)结合广角/小角散射(WAXS/SAXS)实现了工业电流密度下铜基催化剂Cu+/Cu0比例动态平衡的原位追踪, 证实Cu+物种作为C-C耦合活性中心的稳定性. X射线荧光成像(XRF)进一步量化了Cs+电迁移诱导的阴极水淹机制, 揭示阳离子跨膜迁移与碳酸盐沉淀的关联性. 在界面反应微环境解析领域, 原位拉曼光谱通过HCO3-/CO32-特征峰比率, 动态监测阴极表面pH梯度演变, 并捕捉到C2+路径关键中间体*CCO的吸附构型. 衰减全反射-表面增强红外光谱则证实强氢键水网络(sh-H2O)抑制析氢副反应并稳定*COOH中间体. 针对膜电极的电化学诊断, 嵌入式四电极技术解耦了膜-催化剂界面过电位对全池能效的制约. 弛豫时间分布分析从电化学阻抗谱中分离出六类极化过程, 精准定位水淹为MEA失效主因. 上述技术联用进一步颠覆了传统静态模型的认知局限, XAS与SAXS协同证实Ag催化剂在碱性微环境下的溶解-再沉积循环导致活性衰减. XRF与WAXS联用定量表征了电渗流驱动的Cs+迁移通量与GDE孔隙阻塞的关联性. 整合加速应力测试协议和脉冲电压循环结合多模态表征成功预测银催化剂的溶解-再结晶为寿命限制步骤, 为抗降解电极设计提供动力学依据.
未来膜电极原位表征技术的进一步突破需依赖多原位表征联用平台(如同步辐射-拉曼-质谱联用), 在多尺度上关联催化剂动态、膜-电极界面反应与系统衰减, 从而指导高选择性、稳定性的膜电极设计. 在未来, 原位表征技术将实现从“观测工具”向“设计指南”的转型, 是推动CO2电解技术迈向规模化的核心驱动力.

关键词: 原位表征, 膜电极组件, CO2电催化还原, 界面动态, 降解机制

Abstract:

Membrane electrode assemblies (MEAs) represent the preeminent configuration for industrial-scale CO2 electrolysis, yet their dynamic interfaces and degradation pathways remain inadequately resolved. This perspective highlights how advanced operando characterization techniques—synchrotron X-ray spectroscopy, spatially resolved X-ray fluorescence, vibrational spectroscopy, electrochemical diagnostics et al.—decipher atomic-scale catalyst evolution, transient ion/water fluxes, and extreme interfacial microenvironments under industrial current densities. These methodologies reveal critical degradation mechanisms, including catalyst restructuring, carbonate precipitation-driven flooding, and cation-induced pH gradients, which are inaccessible to conventional ex-situ or three-electrode analyses. Integrating multimodal characterization is paramount to correlate transient interfacial chemistry with system-level performance, guiding the rational design of durable, high-selectivity MEAs for scalable CO2 conversion.

Key words: Operando characterization, Membrane electrode assemblies, Electrocatalytic CO2 reduction, Interfacial dynamics, Degradation pathways