Active Edge‐Site‐Rich Carbon Nanocatalysts with Enhanced Electron Transfer for Efficient Electrochemical Hydrogen Peroxide Production

A carbon nanocatalyst that is rich in active edge sites is developed, which shows high activity and selectivity for electrochemical H₂O₂ production. The H₂O₂ production activity surpasses previously reported catalysts in alkaline media, and can sustainably produce H₂O₂ for 16 h with Faradaic efficiency reaching 99 %. The superior activity can be correlated to the enhanced electron transfer capabilities of the (oxygenated) edge‐rich carbon.

Abstract

A highly efficient, metal‐free carbon nanocatalyst is presented that possesses abundant active, oxygenated graphitic edge sites. The edge site‐rich nanocarbon catalyst exhibits about 28 times higher activity for H₂O₂ production than a basal plane‐rich carbon nanotube with a H₂O₂ selectivity over 90 %. The oxidative treatment further promotes the H₂O₂ generation activity to reach close to the thermodynamic limit. The optimized nanocarbon catalyst shows a very high H₂O₂ production activity, surpassing previously reported catalysts in alkaline media. Moreover, it can stably produce H₂O₂ for 16 h with Faradaic efficiency reaching 99 % and accumulated H₂O₂ concentration of 24±2 mm. Importantly, we find that the heterogeneous electron transfer kinetics of the carbon‐based catalyst is closely related to the electrocatalytic activity, suggesting that first outer‐sphere electron transfer to O₂ is an important step governing the H₂O₂ production rate.

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