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

摘要

Electrochemical hydrogen peroxide (H_(2)O_(2)) 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 H_(2)O_(2) production of a number of distinct nitrogen-doped mesoporous carbon catalysts and report a previously unachieved H_(2)O_(2) 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 H_(2)O_(2) product yield and the surface area and interfacial zeta potential. Nitrogen doping was found to sharply boost H_(2)O_(2) activity and selectivity. Chronoamperometric H_(2)O_(2) electrolysis confirms the exceptionally high H_(2)O_(2) production rate and large H_(2)O_(2) faradaic selectivity for the optimal nitrogen-doped CMK-3 sample in acidic, neutral, and alkaline solutions. In alkaline solution, the catalytic H_(2)O_(2) yield increases further, where the production rate of the HO_(2)~(–) anion reaches a value as high as 561.7 mmol g_(catalyst)~(–1) h~(–1) with H_(2)O_(2) faradaic selectivity above 70%. Our work provides a guide for the design, synthesis, and mechanistic investigation of advanced carbon-based electrocatalysts for H_(2)O_(2) production.