In Situ Electrochemical Stress Measurements Examining the Oxygen Evolution Reaction in Basic Electrolytes

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• 作者：Thao T. H. Hoang ; Yair Cohen ; Andrew A. Gewirth
• 刊名：Analytical Chemistry
• 出版年：2014
• 出版时间：November 18, 2014
• 年：2014
• 卷：86
• 期：22
• 页码：11290-11297
• 全文大小：388K
• ISSN：1520-6882

文摘

In situ electrochemical stress measurements are used to interrogate changes in oxide structure before and during the oxygen evolution reaction (OER) from Ir, Ni, Co, Au, and Pt electrodes in alkaline electrolyte. Stress evolution during potential cycling reports on changes in oxidation state and oxide forms. Hysteresis observed in the potential-dependent stress from Ir, Au, and Pt electrodes is associated with chemical irreversibility in electrode composition and roughness. Alternatively, Ni and Co exhibit reversible conversion between hydroxide and oxyhydroxide forms during cycling. From the experimentally determined stress, charge passed during electrode oxidation, and Young鈥檚 modulus, the change in strain exhibited by Ni and Co electrodes during hydroxide-oxyhydroxide conversion is calculated to be 7.0% and 8.4%, respectively. We also show that the magnitude of change in stress is proportional to the amount of material that is further oxidized.