文章基本信息

标题：Role of water structure in alkaline water electrolysis
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作者：Anku Guha ; Mihir Sahoo ; Khorsed Alam 等
期刊名称：iScience
印刷版ISSN：2589-0042
出版年度：2022
卷号：25
期号：8
页码：1-17
DOI：10.1016/j.isci.2022.104835
语种：English
出版社：Elsevier
摘要：SummaryHerein, with the help of experimental and first-principles density functional theory (DFT)-based studies, we have shown that structural changes in the water coordination in electrolytes having high alkalinity can be a possible reason for the reduced catalytic activity of platinum (Pt) in high pH. Studies withpolycrystallinePt electrodes indicate that electrocatalytic HER activity reduces in terms of high overpotential required, high Tafel slope, and high charge transfer resistances in concentrated aqueous alkaline electrolytes (say 6 M KOH) in comparison to that in low alkaline electrolytes (say 0.1 M KOH), irrespective of the counter cations (Na+, K+, or Rb+) present. The changes in the water structure of bulk electrolytes as well as that in electrode-electrolyte interface are studied. The results are compared with DFT-based analysis, and the study can pave new directions in studying the HER process in terms of the water structure near the electrode-electrolyte interface.Graphical abstractDisplay OmittedHighlights•A mechanistic insight into the alkaline hydrogen evolution reaction (HER) is provided•The role of water structure/coordination variation in HER kinetics is studied•The interfacial water structure variation is studied usingin situRaman studies•The Pt−H coverage changes during the HER process are also investigatedChemistry; Electrochemistry; Electrochemical energy production; Computational chemistry