Electrochemical oxygen reduction has been regarded as a promising choice to enable H₂O₂ on-site production and utilization wherein the exploration of high-efficiency yet cost-effective catalysts is the key. Here, we demonstrate a low-cost activated coke (AC) electrocatalyst with size-tailored amorphous carbon clusters doped by oxygen groups, prepared through a facile CO₂ assisted mechanochemistry approach, to deliver among the highest performances reported in a typical alkaline system, including high activity (onset potential of 0.83 V), high H₂O₂ selectivity (∼90 %) and long-term stability. A series of control experiments, structural characterizations before and after electrochemical tests and density functional theory calculations provide a new insight into the coupling role of carbon cluster size and oxygen doping in H₂O₂ electrochemical production process, that is, size-reduced amorphous carbon lattices with abundant edges contribute to the high activity, while the basal carbon atoms in ether-doped small-size carbon plane are the most active sites towards H₂O₂ selectivity.

电化学氧还原已被认为是实现H ₂ O ₂现场生产和利用的有前途的选择，其中探索高效但具有成本效益的催化剂是关键。在这里，我们展示了一种低成本的活性炭（AC）电催化剂，该催化剂具有通过氧基团掺杂的尺寸定制的无定形碳簇，通过一种便捷的CO ₂辅助机械化学方法制备，可实现典型碱体系中报告的最高性能，包括高活性（起始电势为0.83 V），高H ₂ O ₂选择性（〜90％）和长期稳定性。一系列控制实验，电化学测试前后的结构表征以及密度泛函理论计算为H ₂ O ₂电化学生产过程中碳簇尺寸和氧掺杂的耦合作用提供了新的见解，即减小尺寸的无定形碳具有丰富边缘的晶格有助于高活性，而在掺杂醚的小尺寸碳平面中基础碳原子是朝H ₂ O ₂选择性最活跃的位点。