Phosphorus doped hierarchical porous carbon: an efficient oxygen reduction electrocatalyst for on-site H2O2 production

Abstract

The electrochemical oxygen reduction reaction through a two-electron process (2e⁻ ORR) has been considered a promising alternative for on-site hydrogen peroxide (H₂O₂) production. Nevertheless, exploring low-cost and stable electrocatalysts with higher activity and selectivity remains a great challenge in practical applications. Herein, a novel phosphorus-doped macro/meso/micro-porous carbon (P-MC) electrocatalyst was successfully synthesized using sodium phytate (SP) as the precursor, which can not only change the electronic structure of carbon by P-doping, but also regulate the pore structure of the material with self-decomposition. Therefore, the prepared P-MC possesses excellent electrocatalytic performance and stability for 2e⁻ ORR. When tested in 0.1 M KOH, the P-MC exhibits an outstanding faradaic efficiency (FE%) over 98% (0.3 V–0.5 V vs. RHE) and a higher H₂O₂ yield of 8.4 mol h⁻¹ g_cat.⁻¹, which is 16.8 times higher than that of MC prepared with glucose as a precursor (0.5 mol h⁻¹ g_cat.⁻¹). Interestingly, the on-site produced H₂O₂ can be successfully used for efficient disinfection and water treatment, which can solve the problems of high cost, environmental pollution, and potential risks in current H₂O₂ industrial production. This study provides a convenient strategy for designing highly active carbon-based electrocatalysts by simultaneously regulating their electronic and pore structure.