Efficient Electrochemical Hydrogen Peroxide Production from Molecular Oxygen on Nitrogen-Doped Mesoporous Carbon Catalysts

Electrochemical hydrogen peroxide (H₂O₂) production by two-electron oxygen reduction is a promising alternative process to the established industrial anthraquinone process. Current challenges relate to finding cost-effective electrocatalysts with high electrocatalytic activity, stability, and product selectivity. Here, we explore the electrocatalytic activity and selectivity toward H₂O₂ production of a number of distinct nitrogen-doped mesoporous carbon catalysts and report a previously unachieved H₂O₂ selectivity of ∼95–98% in acidic solution. To explain our observations, we correlate their structural, compositional, and other physicochemical properties with their electrocatalytic performance and uncover a close correlation between the H₂O₂ product yield and the surface area and interfacial zeta potential. Nitrogen doping was found to sharply boost H₂O₂ activity and selectivity. Chronoamperometric H₂O₂ electrolysis confirms the exceptionally high H₂O₂ production rate and large H₂O₂ faradaic selectivity for the optimal nitrogen-doped CMK-3 sample in acidic, neutral, and alkaline solutions. In alkaline solution, the catalytic H₂O₂ yield increases further, where the production rate of the HO₂^– anion reaches a value as high as 561.7 mmol g_catalyst^–1 h^–1 with H₂O₂ faradaic selectivity above 70%. Our work provides a guide for the design, synthesis, and mechanistic investigation of advanced carbon-based electrocatalysts for H₂O₂ production.