Benchmarking the Performance of Thin-Film Oxide Electrocatalysts for Gas Evolution Reactions at High Current Densities

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• 作者：Alberto Ganassin ; Artjom Maljusch ; Viktor Colic ; Lukas Spanier ; Kurt Brandl ; Wolfgang Schuhmann ; Aliaksandr Bandarenka
• 刊名：ACS Catalysis
• 出版年：2016
• 出版时间：May 6, 2016
• 年：2016
• 卷：6
• 期：5
• 页码：3017-3024
• 全文大小：484K
• 年卷期：0
• ISSN：2155-5435

文摘

Oxide materials are among the state-of-the-art heterogeneous electrocatalysts for many important large-scale industrial processes, including O₂ and Cl₂ evolution reactions. However, benchmarking their performance is challenging in many cases, especially at high current densities, which are relevant for industrial applications. Serious complications arise particularly due to (i) the formation of a nonconducting gas phase which blocks the surface during the reactions, (ii) problems in determination of the real electroactive electrode area, and (iii) the large influence of surface morphology alterations (stability issues) under reaction conditions, among others. In this work, an approach overcoming many of these challenges is presented, with a focus on electrochemically formed thin-film oxide electrocatalysts. The approach is based on benefits provided by the use of microelectrodes, and it gives comprehensive information about the surface roughness, catalyst activity, and stability. The key advantages of the proposed method are the possibility of characterization of the whole microelectrode surface by means of atomic force microscopy and an accurate assessment of the specific activity (and subsequently stability) of the catalyst, even at very high current densities. Electrochemically deposited CoO_x thin films have been used in this study as model catalysts.