Hydrogen peroxide (H₂O₂), an important industrial chemical, is currently produced through an energy-intensive anthraquinone process that is limited to large-scale facilities. Small-scale decentralized electrochemical production of H₂O₂ via a two-electron oxygen reduction reaction (ORR) offers unique opportunities for sanitization applications and the purification of drinking water. The development of inexpensive, efficient, and selective catalysts for this reaction remains a challenge. Herein, we examine two different porous carbon-based electrocatalysts and show that they exhibit high selectivity for H₂O₂ under alkaline conditions. By rationally varying synthetic methods, we explore the effect of pore size on electrocatalytic performance. Furthermore, by means of density functional calculations, we point out the critical role of carbon defects. Our theory results show that the majority of defects in graphene are naturally selective for the two-electron reduction of O₂ to H₂O₂, and we identify the types of defects with high activity.

中文翻译：

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电化学合成过氧化氢的有缺陷的碳基材料

过氧化氢（H ₂ O ₂）是一种重要的工业化学品，目前是通过能源密集型蒽醌工艺生产的，该工艺仅限于大型设施。通过二电子氧还原反应（ORR）进行的小规模分散电化学生产H ₂ O ₂为消毒应用和饮用水净化提供了独特的机会。开发用于该反应的廉价，有效和选择性的催化剂仍然是挑战。本文中，我们研究了两种不同的多孔碳基电催化剂，并显示它们对H ₂ O _2的选择性高在碱性条件下。通过合理地改变合成方法，我们探索了孔径对电催化性能的影响。此外，通过密度泛函计算，我们指出了碳缺陷的关键作用。我们的理论结果表明，石墨烯中的大多数缺陷对于O ₂到H ₂ O ₂的两电子还原自然是选择性的，并且我们确定了高活性缺陷的类型。