文章基本信息

标题：Achieving delafossite analog by in situ electrochemical self-reconstruction as an oxygen-evolving catalyst
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作者：Juzhe Liu ; Qi Hu ; Yu Wang 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2020
卷号：117
期号：36
页码：21906-21913
DOI：10.1073/pnas.2009180117
出版社：The National Academy of Sciences of the United States of America
摘要：Development of novel and robust oxygen evolution reaction (OER) catalysts with well-modulated atomic and electronic structure remains a challenge. Compared to the well-known metal hydroxides or (oxyhydr)oxides with lamellar structure, delafossites (ABO 2 ) are characterized by alternating layers of A cations and edge-sharing BO 2 octahedra, but are rarely used in OER due to their poor electron conductivity and intrinsic activity. Here, we propose a delafossite analog by mutation of metal oxyhydroxide and delafossite based on first-principles calculations. Modulation on the electronic structure due to distortion of the original crystal field of the BO 2 layers is calculated to enhance electron conductivity and catalytic activity. Inspired by the theoretical design, we have experimentally realized the delafossite analog by electrochemical self-reconstruction (ECSR). Operando X-ray absorption spectroscopy and other experimental techniques reveal the formation of delafossite analog with Ag intercalated into bimetallic cobalt–iron (oxyhydr)oxide layers from a metastable precursor through amorphization. Benefitting from the featured local electronic and geometric structures, the delafossite analog shows superior OER activity, affording a current density of 10 mA⋅cm −2 at an overpotential of 187 mV and an excellent stability (300 h) in alkaline conditions.
关键词：delafossite analog ; electrochemical self-reconstruction ; oxygen evolution reaction ; amorphization ; enhanced activity