image: Since magnetic field does not influence HER or OER in electrolytes of various pH, together with the fact that H+ and OH- transport follows Grotthuss mechanism, researchers propose H2O, rather than H+ or OH-, may act as the universal reactant for HER and OER across various pH. view more
Credit: Chinese Journal of Catalysis
Electrochemical water splitting consists of two elementary reactions i.e., hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Developing robust HER and OER technologies necessitates a molecular picture of reaction mechanism, yet the reactants for water splitting reactions are unfortunately not fully understood.
Recently, a research team led by Zhichuan J. Xu from Nanyang Technological University, Singapore, utilized magnetic field to understand proton transport in HER, and hydroxide ion transport in OER, to discuss the possible implications on understanding the reactants for HER and OER. Magnetic field is a known tool for changing the movement of charged species like ions, e.g. the magnetic-field-improved Cu2+ transportation near the electrode in Cu electrodeposition. However, applying a magnetic field does not affect the HER or OER rate across various pH, which challenges the traditional opinion that charged species (i.e. proton and hydroxide ion) act as the reactant. This anomalous response of HER and OER to magnetic field, and the fact that the transport of proton and hydroxide ion follow Grotthuss mechanism, collectively indicate water may act as the universal reactant for HER and OER across various pH. With the aid of magnetic field, this work serves as an understanding of water might be the reactant in HER and OER, and possibly in other electrocatalysis reactions involving protonation and deprotonation step. A model that simply focuses on the charged species but overlooking the complexity of the whole electrolyte phase where water is the dominant species, may not reasonably reflect the electrochemistry of HER and OER in aqueous electrolyte. The results were published in Chinese Journal of Catalysis (DOI: 10.1016/S1872-2067(21)63821-4).
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About the Journal
Chinese Journal of Catalysis is co-sponsored by Dalian Institute of Chemical Physics, Chinese Academy of Sciences and Chinese Chemical Society, and it is currently published by Elsevier group. This monthly journal publishes in English timely contributions of original and rigorously reviewed manuscripts covering all areas of catalysis. The journal publishes Reviews, Accounts, Communications, Articles, Highlights, Perspectives, and Viewpoints of highly scientific values that help understanding and defining of new concepts in both fundamental issues and practical applications of catalysis. Chinese Journal of Catalysis ranks among the top six journals in Applied Chemistry with a current SCI impact factor of 8.271. The Editors-in-Chief are Profs. Can Li and Tao Zhang.
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