催化学报

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透散电极原位重构AgZn3用于安培级CO2电还原

刘小虎a,1, 李守杰a,1, 毛佳宁a,c,1, 陈奥辉a, 董笑a,*, 韦懿恒a, 夏嘉雨a,b, 朱桓毅a,b, 王晓童a,b, 徐子然a,b,c, 李桂花a, 宋艳芳a, 魏伟a,b,*, 陈为a,b,*   

  1. a中国科学院上海高等研究院, 低碳转化科学与工程中心, 上海 201210;
    b中国科学院大学, 北京 100049;
    c中国科学院上海应用物理研究所, 上海 201204
  • 收稿日期:2025-10-30 接受日期:2025-12-18
  • 通讯作者: *电子信箱: dongx@sari.ac.cn (董笑), weiwei@sari.ac.cn (魏伟), chenw@sari.ac.cn (陈为).
  • 作者简介:1共同第一作者.
  • 基金资助:
    中国科学院前瞻战略科技先导专项(XDB1500302, XDA0390402); 国家重点研发项目(2022YFA1504604); 国家自然科学基金(22478408, 22479156, 22302223); 内蒙古自治区科技重大专项项目(2021ZD0020); 河北省现代钢铁产业创新专项(252G4001D); 上海市科委科技创新计划(23DZ1202600, 23DZ1201804); 上海市学术/科技研究带头人计划(23XD1404400); 上海扬帆计划(23YF1453300); 中国科学院青年创新促进会(E224301401); 中国科学院上海分院优秀青年人才计划(E254991ZZ1).

Engineering substitutional AgZn3 on penetration electrodes via in-situ reconstruction for ampere-level CO2 electroreduction

Xiaohu Liua,1, Shoujie Lia,1, Jianing Maoa,c,1, Aohui Chena, Xiao Donga,*, Yiheng Weia, Jiayu Xiaa, b, Huanyi Zhua,b, Xiaotong Wanga,b, Ziran Xua,b,c, Guihua Lia, Yanfang Songa, Wei Weia,b,*, Wei Chena,b,*   

  1. a Low-Carbon Conversion Science and Engineering Center, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China;
    b University of Chinese Academy of Sciences, Beijing 100049, China;
    c Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, China
  • Received:2025-10-30 Accepted:2025-12-18
  • Contact: *E-mail: dongx@sari.ac.cn (X. Dong), weiwei@sari.ac.cn (W. Wei), chenw@sari.ac.cn (W. Chen).
  • About author:1Contributed equally to this work.
  • Supported by:
    Strategic Priority Research Program of the Chinese Academy of Sciences (XDB1500302, XDA0390402), the National Key R&D Program of China (2022YFA1504604), the National Natural Science Foundation of China (22478408, 22479156, 22302223), the Major Project of the Science and Technology Department of Inner Mongolia (2021ZD0020), the Special Project for Innovation in Modern Steel Industry of Hebei Province (252G4001D), the Science and Technology Innovation Plan of Shanghai Science and Technology Commission (23DZ1202600, 23DZ1201804), Program of Shanghai Academic/Technology Research Leader (23XD1404400), the Shanghai Sailing Program (23YF1453300), the Youth Innovation Promotion Association of Chinese Academy of Sciences (E224301401), the Outstanding Young Talent Project of Shanghai Advanced Research Institute, Chinese Academy of Sciences (E254991ZZ1).

摘要: 电化学还原二氧化碳(eCO2RR)为高附加值化学品(如CO)是缓解碳排放和实现碳循环经济的重要途径. 然而, eCO2RR面临高过电位、竞争性析氢反应(HER)以及工业级电流密度下催化剂稳定性不足等关键挑战. 贵金属(如Ag)对CO选择性高, 但成本昂贵, 储量丰富的锌(Zn)催化剂却本征活性受限, 因此可以通过将痕量Ag与Zn合金化的策略以调节电子结构、优化反应能垒并平衡成本与性能. 本研究提出通过电化学诱导的原位重构策略, 在具有独特传质优势的透散电极上构筑高分散的合金活性界面, 旨在协同优化反应物的传质过程.
本文设计并制备了一种表面合金化的银锌中空纤维透散电极(Ag-Zn HPE), 无需高温固相反应, 而是通过化学置换、氧化烧结及电化学还原结合的方法制备. 首先在Zn中空纤维粗胚上引入微量银物种, 经烧结形成Ag-ZnO中空纤维前驱体. 随后在电化学还原过程中, 电场驱动下原本与氧化锌基底相分离的银物种发生结构重构, 与Zn基底合金化形成高度分散的AgZn3合金相. 多种结构表征表明, 电化学重构使原本团聚的Ag2O/Ag纳米团簇均匀分散并嵌入Zn晶格, 形成了Ag-Zn合金活性位点, 同时电极仍然保持了中空纤维的多孔透散结构. 在3.0 mol L-1 KCl电解液中, 该Ag-Zn合金透散电极表现出优异的CO2电还原性能, 在1.2 A cm-2的高电流密度下CO法拉第效率保持在91%以上, 并稳定运行超过150 h. 对比纯Zn透散电极, 合金电极在宽电位范围内显示出更低的过电位, 其CO分电流密度在-1.20 V vs. RHE时可达1.39 A cm-2, 技术经济分析进一步表明其CO生产成本更低, 展现出良好的工业化应用前景. 此外, 透散效应的理论电流密度和电化学表征表明, 独特的中空纤维结构可强制CO2气体直接穿透表面合金化的多孔壁到达活性位点, 有效克服了传统扩散模式下因CO2低溶解度带来的传质限制, 使电催化在较高电流下仍由eCO2RR主导. 理论计算表明, 合金化调控了Zn的电子结构, 使其d带中心上移, 优化了关键中间体*COOH的吸附和*CO的脱附能垒, 同时有效抑制了HER副反应.
综上, 本工作通过电化学原位重构策略, 在具有高效传质结构的中空纤维透散电极上构筑高活性AgZn3合金位点, 实现了CO2在高电流密度下向CO的高效转化, 阐明了合金化和透散效应对反应动力学的调控机制, 为面向工业应用的电极设计提供了新思路.

关键词: CO2电还原, 结构重构, 电催化剂, 中空纤维透散电极, 银锌合金

Abstract: The electrochemical reduction of CO2 to CO offers a promising route for mitigating carbon emissions and producing sustainable feedstocks. Although noble metals like Ag exhibit high CO selectivity, their high cost and scarcity hinder scalability. Earth-abundant Zn catalysts suffer from intrinsic activity limitations, while alloying with trace Ag would modulate electronic structures for tuning its CO2 electroreduction activity. Herein, a surface-alloyed Ag-Zn hollow-fiber penetration electrode (HPE) is constructed via an electrochemically induced reconfiguration process that transforms the initial phase-separated Ag clusters on ZnO substrate into a homogeneously dispersed Ag-Zn alloy (AgZn3). The resulting Ag-Zn HPE achieves 91% faradaic efficiency for CO at 1.2 A cm-2 and demonstrates long-term electrolysis over 150 hours, as well as promising cost-effectiveness for industrial applications. Combined with the penetration effect that effectively mitigates CO2 mass transport limitations, the HPE enables high-rate CO production even at large current densities. Mechanistic investigations reveal that alloying modifies the d-band center of Zn, strengthens *COOH adsorption and facilitates *CO desorption to boost CO formation while suppressing hydrogen evolution reaction. This work provides fundamental insights into the role of surface alloying in enhancing CO2 reduction kinetics and presents a scalable electrode architecture with significant potential for sustainable CO2 conversion.

Key words: CO2 electroreduction, Structural reconfiguration, Electrocatalyst, Hollow-fiber penetration electrode, Ag-Zn alloy