Hunan Joint International Research Center for Carbon Dioxide Resource Utilization, State Key Laboratory of Powder Metallurgy, School of Physical and Electronics, Central South University, 410083 Changsha, China.
Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, 511443 Guangzhou, China.
J Am Chem Soc. 2022 Aug 17;144(32):14505-14516. doi: 10.1021/jacs.2c01194. Epub 2022 Aug 3.
Electrosynthesis of hydrogen peroxide (HO) through oxygen reduction reaction (ORR) is an environment-friendly and sustainable route for obtaining a fundamental product in the chemical industry. Co-N single-atom catalysts (SAC) have sparkled attention for being highly active in both 2e ORR, leading to HO and 4e ORR, in which HO is the main product. However, there is still a lack of fundamental insights into the structure-function relationship between CoN and the ORR mechanism over this family of catalysts. Here, by combining theoretical simulation and experiments, we unveil that pyrrole-type CoN (Co-N SAC) is mainly responsible for the 2e ORR, while pyridine-type CoN catalyzes the 4e ORR. Indeed, Co-N SAC exhibits a remarkable HO selectivity of 94% and a superb HO 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─with weakening O/HOO* interaction─boosts the HO production.
通过氧还原反应（ORR）电合成过氧化氢（HO）是一种环保且可持续的方法，可用于获得化学工业中的基本产品。钴-氮单原子催化剂（SAC）在 2e ORR 和 4e ORR 中都表现出很高的活性，这两种反应都可以生成 HO，其中 HO 是主要产物，因此备受关注。然而，对于这类催化剂的结构-功能关系以及 ORR 机制，我们仍然缺乏基本的认识。在这里，我们通过理论模拟和实验相结合，揭示了吡咯型 CoN（Co-N SAC）主要负责 2e ORR，而吡啶型 CoN 则催化 4e ORR。事实上，在流动电池中，Co-N SAC 表现出出色的 HO 选择性（94%）和优异的 HO 产率（90 h 内为 2032 mg），在酸性介质中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 通过减弱 O/HOO*相互作用，促进了 HO 的生成。
