碱性介质中氢氧化和析氢反应机理研究现状  

Research Progress of Hydrogen Oxidation and Hydrogen Evolution Reaction Mechanism in Alkaline Media

作　　者：李孟婷 郑星群 李莉[1] 魏子栋[1] Mengting Li;Xingqun Zheng;Li Li;Zidong Wei(The State Key Laboratory of Power Transmission Equipment and System Security and New Technology,Chongqing Key Laboratory of Chemical Process for Clean Energy and Resource Utilization,School of Chemistry and Chemical Engineering,Chongqing University,Chongqing 401331,China)

机构地区：[1]输配电装备及系统安全与新技术国家重点实验室,洁净能源与资源化工过程重庆市重点实验室,重庆大学化学化工学院,重庆401331

出　　处：《物理化学学报》2021年第9期13-29,共17页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(21822803,91834301,21576032)资助项目。

摘　　要：氢氧燃料电池和电解水是实现氢能循环利用的两个重要系统,其中氢氧化反应(HOR)和析氢反应(HER)因在碱性介质中的反应速率较酸性介质中慢2至3个数量级,成为阻碍碱性燃料电池与电解水制氢发展的主要瓶颈。深入研究碱性介质中的HOR/HER机理,探究碱性与酸性电解质中HOR/HER活性差异之根本原因,对发展低温碱性能源转化器件具有重要意义。据此,本文综述了近年来碱性介质中HOR/HER机理的相关解释与推论,如双功能机理、氢结合能(HBE)理论与电子效应,及各观点间存在的争议;并从理论计算的角度,介绍了目前电化学界面的理论模拟方法及其在HOR/HER研究中的应用。由于电化学反应系统的复杂性,实验与理论计算的结合有助于理清HOR/HER的机理以及pH效应,并有望应用于指导设计高活性、高稳定性的HOR/HER催化剂。Hydrogen oxygen fuel cells and water electrolysis serves as two important systems for realizing the recycling of hydrogen energy,which involves two crucial electrochemical reactions,the hydrogen oxidation reaction(HOR)and the hydrogen evolution reaction(HER).The kinetics of HOR/HER in alkaline media is 2 or 3 orders of magnitude slower than that in acidic media,which is the main bottleneck that hinders the development of alkaline membrane fuel cells and alkaline water electrolysis.Thus,clarifying the underlying difference of HOR/HER activity in alkaline and acid electrolytes,and exploring the alkaline HOR/HER mechanism are the significant challenges for widely commercial application of low temperature alkaline energy conversion devices.Here,this paper briefly reviews the related explanations and controversies about the alkaline HOR/HER mechanism in recent years,including bifunctional mechanism,hydrogen binding energy(HBE)theory and electronic effect.The bifunctional mechanism emphasizes the influence of water dissociation and OH adsorption on HER and HOR,respectively,which possesses guiding significance for designing and fabricating composite catalysts.The HBE theory stresses that Had is the key reaction intermediate of HOR/HER,and other external factors,such as electrode potential,pH,ions and so on,affect the HOR/HER mechanism and kinetics by disturbing HBE.HBE is widely considered to be the only activity descriptor of HOR/HER.The electronic effect emphasizes the role of catalysts’composition and reaction intermediates in regulating electronic structure of active sites and changing HOR/HER mechanism.It provides an effective strategy to construct active sites and optimize catalytic activity.In addition,we summarize the theoretical simulation methods of electrochemical interface and their applications in exploring HOR/HER mechanism.In-depth theoretical simulation of HOR/HER mechanism requires the establishment of a more reasonable explicit solvation model on electrode/electrolyte interface and the combination of

关 键 词：燃料电池 电解水 氢氧化反应 析氢反应 PH效应 密度泛函理论 分子动力学 

分 类 号：O646[理学—物理化学]