O,N Co-Modulated Carbon Catalysts and Optimized Gas Diffusion Electrodes for Electrochemical H2O2 Production

Abstract

The large-scale production of sustainable aviation fuels (SAFs) heavily relies on hydrogen supply, while traditional hydrogen storage and delivery suffer from safety risks and high cost. Hydrogen peroxide (H2O2) is regarded as a promising hydrogen carrier, which can be produced on-site through a green electrochemical two-electron oxygen reduction reaction (2e– ORR). Herein, oxygen, nitrogen co-modulated carbon (O-NC) catalysts were fabricated by doping N dopants and oxygen-containing functional groups (OFGs). The pyrrolic N is revealed to jeopardize the electronic structure of the NC catalyst, and the OFGs can further regulate the NC matrix for 2e– ORR. As a result, the optimized O-NC-5 catalyst exhibits an excellent H2O2 selectivity of over 80% in both alkaline and neutral electrolytes. After further optimizing Nafion content, catalyst loading, and operating conditions of O-NC-5-based gas diffusion electrodes, the assembled flow cell can deliver a high H2O2 yield of 3.4 mol gcat–1 h–1 and Faradaic efficiency of above 90%, with robust stability over 12 h. This work reveals the synergistic effects of N dopants and OFGs toward 2e– ORR performance and offers a feasible strategy to develop high-performance carbon electrocatalysts and practical electrode systems for green H2O2 production, which supports the SAF synthesis.