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Zusammenfassung:
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 gcatalyst–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.
