Enhancement of Mass Transfer for Facilitating Industrial-Level CO2 Electroreduction on Atomic Ni-N4 Sites

Herein, an active catalyst A-Ni@CMK is developed with the atomically dispersed Ni-N-4 moieties on the mesoporous carbon for the electrocatalytic CO2 reduction reaction (CO2RR) through a step-by-step pore-filling synthetic strategy. Concretely, the as-synthesized catalyst A-Ni@CMK exhibits outstanding catalytic performance for CO2RR in the H-cell with a Faradaic efficiency of CO (FECO) > 80% in a wide electrochemical potential window (-0.5 to -0.9 V vs RHE) and a large CO partial current density (j(CO)) of 24 and 51 mA cm(-2) at -0.6 and -0.8 V versus RHE, respectively. Notably, j(CO) for A-Ni@CMK can further reach the industrial-level values of 366 mA cm(-2) at -0.8 V versus RHE, respectively, with the FECO > 95% in the flow cell, surpassing those for all the thus far reported Ni-N-C catalysts and representing one of the best values for the catalysts for CO2RR. Moreover, comparative experimental studies in combination with density functional theory calculations demonstrate that the intrinsic high activity of the atomic Ni-N-4 sites towards CO2RR results in high selectivity. Nevertheless, the mesoporous channels favor the mass transmission for both reactant CO2 and gas-product CO, which in turn enhances the reaction kinetics, leading to the improved overall performance of the as-prepared A-Ni@CMK catalyst for CO2-to-CO conversion.