Atomically Dispersed Iridium on Indium Tin Oxide Efficiently Catalyzes Water Oxidation
Atomically Dispersed Iridium on Indium Tin Oxide Efficiently Catalyzes Water Oxidation
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DOI：
10.1021/acscentsci.0c00604
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发表时间：
2020-07-22
影响因子：
18.2
通讯作者：
Coperet, Christophe
中科院分区：
文献类型：
--
作者：
Lebedev, Dmitry;Ezhov, Roman;Coperet, Christophe
在载体上以原子分散的金属形式的多相催化剂提供了活性组分的最有效利用，这对于稀缺和昂贵的后过渡金属尤其重要。这些催化剂也使独特的机会，了解反应途径，通过详细的光谱和计算研究。在这里，我们表明，原子分散的铱网站上的铟锡氧化物通过表面有机金属化学制备显示示范性的催化活性，在最具挑战性的电化学过程之一，析氧反应（OER）。原位X射线吸收研究表明，形成的Ir-V=O的OER条件下的Ir-O距离为1.83埃的中间体。反应机理的建模表明，Ir-V=O可能是一种催化剂的静止状态，随后被氧化为Ir-VI，使快速的水亲核攻击和氧的释放。我们预计，所应用的策略可以有助于制备和研究广泛的原子分散的过渡金属催化剂的导电氧化物（光）电化学应用。
Heterogeneous catalysts in the form of atomically dispersed metals on a support provide the most efficient utilization of the active component, which is especially important for scarce and expensive late transition metals. These catalysts also enable unique opportunities to understand reaction pathways through detailed spectroscopic and computational studies. Here, we demonstrate that atomically dispersed iridium sites on indium tin oxide prepared via surface organometallic chemistry display exemplary catalytic activity in one of the most challenging electrochemical processes, the oxygen evolution reaction (OER). In situ X-ray absorption studies revealed the formation of Ir-V=O intermediate under OER conditions with an Ir-O distance of 1.83 angstrom. Modeling of the reaction mechanism indicates that Ir-V=O is likely a catalyst resting state, which is subsequently oxidized to Ir-VI enabling fast water nucleophilic attack and oxygen evolution. We anticipate that the applied strategy can be instrumental in preparing and studying a broad range of atomically dispersed transition metal catalysts on conductive oxides for (photo) electrochemical applications.