Identification of in situ Generated Iron-Vacancy Induced Oxygen Evolution Reaction Kinetics on Cobalt Iron Oxyhydroxide
作者机构：College of Chemistry and Molecular SciencesWuhan UniversityWuhanHubei430072 China
出 版 物：《Chinese Journal of Chemistry》 (中国化学（英文版）)
年 卷 期：2024年第42卷第4期
页 面：343-350页
核心收录：
学科分类：07[理学] 070304[理学-物理化学(含∶化学物理)] 0703[理学-化学]
基 金：supported by the National Natural Science Foundation of China(22272121,21972107) the Fundamental Research Funds for the Central Universities(2042022kf1179).
主 题：CoFe oxyhydroxide Oxygen evolution reaction Fe vacancy Electrocatalysis Kinetics Reaction mechanisms
摘 要：Developing highly efficient and low-cost electrocatalysts towards oxygen evolution reaction(OER)is essential for practical application in water electrolyzers and rechargeable metal-air batteries.Although Fe-based oxyhydroxides are regarded as state-of-the-art non-noble OER electrocatalysts,the origin of performance enhancement derived from Fe doping remains a hot topic of considerable discussion.Herein,we demonstrate that in situ generated Fe vacancies in the pristine CoFeOOH catalyst through a pre-conversion process during alkaline OER result from dynamic Fe dissolution,identifying the origin of Fe-vacancy-induced enhanced OER kinetics.Density functional theory(DFT)calculations and experimental results including X-ray absorption fine-structure spectroscopy,in situ UV-Vis spectroscopy,and in situ Raman spectroscopy reveal that the Fe vacancies could significantly promote the d-band center and valence states of adjacent Co sites,alter the active site from Fe atom to Co atom,accelerate the formation of high-valent active Co^(4+)species,and reduce the energy barrier of the potential-determining step,thereby contribute to the significantly enhanced OER performance.
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