Author(s): Swierk, JR; Tilley, TD | Abstract: © The Author(s) 2017. Cobalt oxides are an earth abundant material that exhibits high electrocatalytic activity for the oxygen evolution reaction (OER) across a wide pH range. Recent studies suggest that OER catalysis can proceed through an active site comprised of one or two cobalt atoms but that multiple adjacent cobalt centers are preferred to stabilize high valent cobalt oxo-intermediates by delocalization. Utilizing molecular precursors to prepare single, isolated cobalt atoms (SS-Co) and small clusters of Co3O4 we find that OER proceeds more efficiently on Co3O4. Using electrochemical impedance spectroscopy (EIS), these results were rationalized at an atomic level. The EIS results support a hypothesis that charge transfer related to the formation of reaction intermediates proceeds more easily on Co3O4 than on SS-Co, which is attributed to the difficulty in forming Co(IV) = O and unlikely nucleophilic attack by water to form Co(II)-OOH.

中文翻译：

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钴的单中心和小核团簇的电催化水氧化

作者（S）：Swierk，JR；蒂利，TD | 摘要：© The Author(s) 2017。钴氧化物是一种地球丰富的材料，在很宽的 pH 范围内对析氧反应 (OER) 表现出高电催化活性。最近的研究表明，OER 催化可以通过由一个或两个钴原子组成的活性位点进行，但优选多个相邻的钴中心通过离域稳定高价钴氧代中间体。利用分子前体制备单个、孤立的钴原子 (SS-Co) 和 Co3O4 小簇，我们发现 OER 在 Co3O4 上更有效地进行。使用电化学阻抗谱 (EIS)，这些结果在原子水平上得到了合理化。