催化学报 ›› 2022, Vol. 43 ›› Issue (5): 1351-1359.DOI: 10.1016/S1872-2067(21)63935-9

• 论文 • 上一篇    下一篇

过渡金属单原子功能化碳载体促进碱性氢电催化反应动力学

李鹏a, 赵国强a,b(), 程宁燕a, 夏力学c, 李晓宁a, 陈亚平b, 劳梦梦a, 程振祥a, 赵焱c,d, 徐迅a(), 姜银珠b, 潘洪革b,e, 窦士学a, 孙文平b()   

  1. a伍伦贡大学超导与电子材料研究所, 伍伦贡2522, 澳大利亚
    b浙江大学材料科学与工程学院, 能源清洁利用国家重点实验室, 浙江杭州310027, 中国
    c武汉理工大学材料科学与工程国际化示范学院, 硅酸盐建筑材料国家重点实验室, 湖北武汉430070, 中国
    d武汉大学工业科学研究院, 湖北武汉430027, 中国
    e西安工业大学新能源科学与技术研究院, 陕西西安710021, 中国
  • 收稿日期:2021-07-27 接受日期:2021-08-30 出版日期:2022-05-18 发布日期:2022-03-23
  • 通讯作者: 赵国强,徐迅,孙文平
  • 基金资助:
    澳大利亚研究基金委(DP200100365);澳大利亚研究基金委(LP160100273);浙江大学“百人计划”;中国博士后科学基金(2021M690132);中国博士后科学基金(2021T140588);博士后国际交流计划引进项目(YJ20200160)

Toward enhanced alkaline hydrogen electrocatalysis with transition metal-functionalized nitrogen-doped carbon supports

Peng Lia, Guoqiang Zhaoa,b(), Ningyan Chenga, Lixue Xiac, Xiaoning Lia, Yaping Chenb, Mengmeng Laoa, Zhenxiang Chenga, Yan Zhaoc,d, Xun Xua(), Yinzhu Jiangb, Hongge Panb,e, Shi Xue Doua, Wenping Sunb()   

  1. aInstitute for Superconducting & Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, NSW 2522, Australia
    bSchool of Materials Science and Engineering, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, Zhejiang, China
    cState Key Laboratory of Silicate Materials for Architectures, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, Hubei, China
    dThe Institute of Technological Sciences, Wuhan University, Wuhan 430072, Hubei, China
    eInstitute of Science and Technology for New Energy, Xi'an Technological University, Xi'an 710021, Shaanxi, China
  • Received:2021-07-27 Accepted:2021-08-30 Online:2022-05-18 Published:2022-03-23
  • Contact: Guoqiang Zhao, Xun Xu, Wenping Sun
  • Supported by:
    Australian Research Council (ARC) through a Discovery Project(DP200100365);a Linkage Project(LP160100273);“Hundred Talents Program” of Zhejiang University;China Postdoctoral Science Foundation(2021M690132);China Postdoctoral Science Foundation(2021T140588);Office of China Postdoc Council(YJ20200160)

摘要:

碱性阴离子膜燃料电池和电解水制氢技术对氢能的高效循环利用非常关键. 然而, 碱性条件下析氢反应(HER)和氢氧化反应(HOR)动力学缓慢, 大大降低了燃料电池和电解池的能量转换效率. 因此, 开发综合性能优异的电催化剂以提高碱性环境下HER和HOR动力学至关重要. 传统电催化剂的一个典型设计思路是将活性材料负载于具有高导电性和大比表面积的碳载体上. 一般来说, 碳载体能够促进活性材料的均匀分散并显著增加其催化活性位点的暴露, 但是碳载体本身往往很难参与电催化反应, 导致复合催化剂活性位点单一, 不利于高效催化涉及较多中间体的复杂反应(碱性条件下的HOR和HER). 另一方面, 当前电催化剂研究通常局限于调控活性材料和载体的界面结构或者专注于调控活性材料本征结构, 对催化剂载体进行调控并作为助催化剂的研究尚不多见.

本文采用过渡金属单原子对碳载体进行功能化及电子结构调控, 并研究此类碳载体在碱性HER和HOR反应中的助催化作用. 合成了一系列金属单原子修饰的碳载体M-N-C (过渡金属包括Mn, Fe, Co, Ni, Cu, Mo, Ag), 并系统研究了M-N-C在Pt电催化HOR和HER中的作用. 结果表明, 过渡金属单原子修饰的碳载体的催化促进作用与过渡金属的电负性以及3d轨道电子填充度密切相关. 一方面, 不同过渡金属M与氧的亲和力不同, 并可以通过界面M-O-Pt键调节Pt的电子结构. 过渡金属电负性越小, Pt表面的电子密度则越大, 有助于加速Had在Pt表面的结合/解离步骤, 因此提升了HOR和HER反应速率. 另一方面, 过渡金属的3d轨道未填充程度越高, 则越有利于增强其与氧2p轨道的耦合作用, 所形成的M-N4结构对于水分子和OHad的吸附也大大增强, 最终通过促进Volmer步骤加快氢的电催化反应速率. 结果显示, 除Cu和Ag单原子修饰的碳载体之外, 其它几种过渡金属功能化的碳载体均能够通过促进Volmer反应步骤以加快碱性条件下Pt的HOR和HER电催化反应速率, 其中效果最为显著的是锰单原子修饰的碳载体. Mn-N-C/Pt (1.48 mA cmPt-2)的质量比交换电流密度比商业化20% Pt/C (0.26 mA cmPt-2)提高了约4.7倍. 综上所述, 本工作证明了开发多功能碳载体用于异相催化反应的重要性, 并且为未来开发高效电催化剂提供了新的思路.

关键词: 多功能载体, 氢氧化反应, 析氢反应, 金属-载体相互作用, 电催化

Abstract:

Superior catalyst supports are crucial to developing advanced electrocatalysts toward heterogeneous catalytic reactions. Herein, we systematically investigate the role of transition metal-functionalized N-doped carbon nanosheets (M-N-C, M = Mn, Fe, Co, Ni, Cu, Mo, and Ag) as the multifunctional electrocatalyst supports toward hydrogen evolution/oxidation reactions (HER/HOR) in alkaline media. The results demonstrate that all the M-N-C nanosheets, except Cu-N-C and Ag-N-C, can promote the alkaline HER/HOR electrocatalytic activity of Pt by accelerating the sluggish Volmer step, among which Mn plays a more significant role. Analyses reveal that the promotion effect of M-N-C support is closely associated with the electronegativity of the metal dopants and the relative filling degree of their d-orbitals. For one, the metal dopant in M-N-C with smaller electronegativity would provide more electrons to oxygen and hence tune the electronic structure of Pt via the M-O-Pt bonds at the interface. For another, the transition metal in M-N4 moieties with more empty d orbitals would hybridize with O 2p orbitals more strongly that promotes the adsorption of water/hydroxyl species. The results demonstrate the conceptual significance of multifunctional supports and would inspire the future development of advanced electrocatalysts.

Key words: Multifunctional support, Hydrogen oxidation reaction, Hydrogen evolution reaction, Metal-support interaction, Electrocatalysis