Electrochemical oxygen reduction (ORR) is a challenging approach for the sustainable production of hydrogen peroxide (H₂O₂) and is also a reaction of relevance in fuel-cell applications. Here, we propose an outstanding metal-free electrocatalyst for the unexpectedly selective ORR to H₂O₂, consisting of graphitized N-doped single-wall carbon nanohorns (CNHs). The catalyst can operate at acidic pH to a faradic efficiency as high as 98%, but it also shows excellent performance at either physiological or alkaline pH. Moreover, the very positive onset potentials observed at all pH values investigated (+0.40 V, +0.53 V, and +0.71 V at pH 1.0, 7.4, and 13.0, respectively), good stability, and excellent reproducibility make this material a benchmark catalyst for ORR to H₂O₂. The outstanding activity arises from a combination of several factors, such as CNH-dependent facilitation of electron delivery, suitable porosity, and a favorable distribution of the types of N atoms.

电化学减氧（ORR）是可持续生产过氧化氢（H ₂ O ₂）的挑战性方法，也是燃料电池应用中相关的反应。在这里，我们提出了一种出色的无金属电催化剂，用于对H ₂ O ₂的意外选择性ORR由石墨化的N掺杂单壁碳纳米角（CNH）组成。该催化剂可在酸性pH值下达到高达98％的法拉第效率，但在生理pH值或碱性pH值下也表现出优异的性能。此外，在所有研究的pH值（在pH 1.0、7.4和13.0时分别为+0.40 V，+ 0.53 V和+0.71 V）中观察到的非常高的起始电位，良好的稳定性和出色的重现性使该材料成为基准催化剂用于ORR至H ₂ O ₂。杰出的活性来自多种因素的组合，例如CNH依赖于电子传递的便利性，合适的孔隙率以及N原子类型的有利分布。