Effect of the interfacial electric field on the HER on Pt(111)modified with iron adatoms in alkaline media  

碱性介质中界面电场对铁原子吸附修饰Pt(111)表面HER性能的影响

作　　者：Francisco J.Sarabia Víctor Climent Juan M.Feliu Francisco J.Sarabia;Víctor Climent;Juan M.Feliu(阿利坎特大学电化学研究所,西班牙阿利坎特)

机构地区：[1]Instituto Universitario de Electroquímica,Universidad de Alicante,Carretera San Vicente del Raspeig s/n,E-03690 San Vicente del Raspeig,Alicante,Spain

出　　处：《Chinese Journal of Catalysis》2022年第11期2826-2836,共11页催化学报（英文）

基　　金：funded by Ministerio de Ciencia e Innovación (Spain) (PID2019-105653GB-I00);Generalitat Valenciana (Spain) (PROMETEO/2020/063)。

摘　　要：The study of the hydrogen evolution reaction(HER)aimed to reach a deeper understanding of the parameters that control the rate of this reaction is of great importance given the technical relevance of hydrogen production as an energy vector in the so-called hydrogen economy.In previous works,laser-induced temperature jump(LITJ)experiments on Pt(111)modified with Ni(OH)_(2)in alkaline media have revealed the importance of the interfacial electric field in the rate of the HER.It was hypothesised that small amounts of Ni(OH)_(2)cause a decrease of the electric field because of a negative shift of the pzfc toward the onset of the hydrogen evolution.In this work,to test the validity of this hypothesis,the study has been extended to Pt(111)surfaces modified with Fe(OH)_(2).The modified surfaces have been studied voltammetrically,and the voltammetric charges have been analysed.The voltammograms show a peak in the hydrogen evolution region that suggest the transformation in the adlayer from Fe(II)to Fe(0).In agreement with the coulometric analysis,the voltammetric features in the OH adsorption region would be related with the oxidation to the+3 valence state.The results obtained with LITJ method reflect the existence of a strong interaction of the Fe oxophilic species with the water molecules,shifting the potential of maximum entropy away from the onset of the HER.Hence,the most catalytic surface is the one with the lowest Fe coverage.鉴于析氢反应(HER)与制氢技术直接相关,而氢气是氢经济中的能量载体,因此,深入理解析氢反应(HER)速率的控制参数非常重要.前期关于碱性介质中Ni(OH)_(2)修饰的Pt(111)上激光诱导温度跃迁(LITJ)实验结果已经揭示了界面电场对HER速率有较大影响.推测认为,少量的Ni(OH)_(2)会使电极的零自由电荷电势向析氢开始的方向负移,从而导致电场减弱.为进一步验证这一推测,本文将研究对象扩展到Fe(OH)_(2)修饰的Pt(111)表面,对其伏安特性进行分析.伏安图在析氢区域显示出一个峰,表明修饰层发生Fe(Ⅱ)到Fe(0)的转变.与库仑分析结果一致,OH吸附区的伏安特征与Fe物种被氧化至+3价有关.LITJ结果显示,亲氧的Fe物质与水分子之间存在强烈的相互作用,其使熵最大处的电势远离HER的开始电势.因此,最具催化性的表面应该是Fe覆盖度最低的表面.

关 键 词：Hydrogen evolution reaction Iron adatoms Platinum single crystal Pt(111) Laser induced temperature jump Interfacial electric field Potential of zero charge 

分 类 号：O647.3[理学—物理化学]