Defective Carbon-Based Materials for the Electrochemical Synthesis of Hydrogen Peroxide

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.