Hao Yaming, Kang Yikun, Wang Shaoyan, Chen Zhe, Lei Can, Cao Xueting, Chen Lin, Li Yefei, Liu Zhipan, Gong Ming
Department of Chemistry and, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, 200438, Shanghai, P. R. China.
Angew Chem Int Ed Engl. 2023 Sep 25;62(39):e202303200. doi: 10.1002/anie.202303200. Epub 2023 Jun 27.
Neutral water oxidation is a crucial half-reaction for various electrochemical applications requiring pH-benign conditions. However, its sluggish kinetics with limited proton and electron transfer rates greatly impacts the overall energy efficiency. In this work, we created an electrode/electrolyte synergy strategy for simultaneously enhancing the proton and electron transfers at the interface toward highly efficient neutral water oxidation. The charge transfer was accelerated between the iridium oxide and in situ formed nickel oxyhydroxide on the electrode end. The proton transfer was expedited by the compact borate environment that originated from hierarchical fluoride/borate anions on the electrolyte end. These concerted promotions facilitated the proton-coupled electron transfer (PCET) events. Due to the electrode/electrolyte synergy, Ir-O and Ir-OO intermediates could be directly detected by in situ Raman spectroscopy, and the rate-limiting step of Ir-O oxidation was determined. This synergy strategy can extend the scope of optimizing electrocatalytic activities toward more electrode/electrolyte combinations.
对于各种需要pH中性条件的电化学应用而言，中性水氧化是一个关键的半反应。然而，其缓慢的动力学过程以及有限的质子和电子转移速率极大地影响了整体能量效率。在这项工作中，我们创建了一种电极/电解质协同策略，用于同时增强界面处的质子和电子转移，以实现高效的中性水氧化。在电极端，氧化铱与原位形成的氢氧化氧镍之间的电荷转移得到了加速。质子转移则通过紧凑的硼酸盐环境得以加快，该环境源自电解质端的分级氟化物/硼酸盐阴离子。这些协同促进作用推动了质子耦合电子转移（PCET）事件。由于电极/电解质的协同作用，通过原位拉曼光谱可以直接检测到Ir-O和Ir-OO中间体，并确定了Ir-O氧化的速率决定步骤。这种协同策略可以将优化电催化活性的范围扩展到更多的电极/电解质组合。
