Atomic-level tuning of Co-N-C catalyst for high-performance electrochemical H_2O_2 production

摘要

Despite the growing demand for hydrogen peroxide it is almost exclusively manufactured by the energy-intensive anthraqui-none process. Alternatively, H_2O_2 can be produced electrochemically via the two-electron oxygen reduction reaction, although the performance of the state-of-the-art electrocatalysts is insufficient to meet the demands for industrialization. Interestingly, guided by first-principles calculations, we found that the catalytic properties of the Co-N_4 moiety can be tailored by fine-tuning its surrounding atomic configuration to resemble the structure-dependent catalytic properties of metalloenzymes. Using this principle, we designed and synthesized a single-atom electrocatalyst that comprises an optimized Co-N_4 moiety incorporated in nitrogen-doped graphene for H_2O_2 production and exhibits a kinetic current density of 2.8 mA cm~(-2) (at 0.65 V versus the reversible hydrogen electrode) and a mass activity of 155 Ag~(-1) (at 0.65 V versus the reversible hydrogen electrode) with negligible activity loss over 110 hours.