Electrosynthesis of hydrogen peroxide (H₂O₂) through oxygen reduction reaction (ORR) is an environment-friendly and sustainable route for obtaining a fundamental product in the chemical industry. Co–N₄ single-atom catalysts (SAC) have sparkled attention for being highly active in both 2e^– ORR, leading to H₂O₂ and 4e^– ORR, in which H₂O is the main product. However, there is still a lack of fundamental insights into the structure–function relationship between CoN₄ and the ORR mechanism over this family of catalysts. Here, by combining theoretical simulation and experiments, we unveil that pyrrole-type CoN₄ (Co–N SAC_Dp) is mainly responsible for the 2e^– ORR, while pyridine-type CoN₄ catalyzes the 4e^– ORR. Indeed, Co–N SAC_Dp exhibits a remarkable H₂O₂ selectivity of 94% and a superb H₂O₂ yield of 2032 mg for 90 h in a flow cell, outperforming most reported catalysts in acid media. Theoretical analysis and experimental investigations confirm that Co–N SAC_Dp─with weakening O₂/HOO* interaction─boosts the H₂O₂ production.

中文翻译：

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用于选择性氧还原生成过氧化氢的高活性 Co-N4 配位基序的鉴定


通过氧还原反应（ORR）电合成过氧化氢（H ₂ O ₂ ）是获得化学工业基础产品的一种环境友好且可持续的途径。 Co-N ₄单原子催化剂(SAC)因其在2e ^– ORR中的高活性而引起人们的关注，产生H ₂ O ₂和4e ^– ORR，其中H ₂ O是主要产物。然而，对于 CoN ₄和该系列催化剂的 ORR 机制之间的结构-功能关系仍然缺乏基本的见解。在这里，通过结合理论模拟和实验，我们揭示了吡咯型CoN ₄ (Co–N SAC _Dp )主要负责2e ^- ORR，而吡啶型CoN ₄催化4e ^- ORR。事实上，Co–N SAC _Dp在流动池中表现出高达 94% 的 H ₂ O ₂选择性和 90 小时内 2032 mg 的出色 H ₂ O ₂产率，在酸性介质中的性能优于大多数报道的催化剂。理论分析和实验研究证实，Co-N SAC _Dp （O ₂ /HOO* 相互作用减弱）可提高 H ₂ O ₂的产量。