析氧
氢氧化物
氧气
电催化剂
催化作用
无机化学
化学
氧还原
材料科学
化学工程
电化学
物理化学
电极
有机化学
工程类
作者
Ting Zhang,Michael R. Nellist,Lisa J. Enman,Jinjuan Xiang,Shannon W. Boettcher
出处
期刊:Chemsuschem
[Wiley]
日期:2018-11-09
卷期号:12 (9): 2015-2021
被引量:57
标识
DOI:10.1002/cssc.201801975
摘要
Ni-Fe (oxy)hydroxide and Co-Fe (oxy)hydroxide are among the most active oxygen evolution reaction (OER) catalysts in alkaline media. Fe is essential for the high activity, but the details of how Fe is incorporated into the Ni or Co (oxy)hydroxide structure and affects catalysis remain incompletely understood. This study concerns two different modes of Fe incorporation to form Co(Fe)Ox Hy , which both yield increased OER activity but result in Fe and Co species that differ in chemical reactivity and electrochemical response. Co(Fe)Ox Hy films that were cathodically deposited from mixed Co and Fe nitrate solution (co-deposited) result in Fe species that interact strongly with the Co species (as evidenced by an anodic shift in the Co redox wave) and are difficult to leach out under electrochemical conditions. Fe incorporated into a CoOx Hy film by cycling in Fe-spiked KOH electrolyte similarly enhance activity, but do not strongly electronically interact with the majority of the Co in the film and are removed by cycling in Fe-free KOH. These results support the hypothesis that co-deposition of Co(Fe)Ox Hy leads to films where the Co and Fe are mixed within the nanosheet structure and cycling in Fe-spiked KOH incorporates Fe species largely at surface, edge, or defect sites, where they drive OER but do not otherwise significantly modulate the electrochemical response of the Co.
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