Synthesizing MOF-derived Ni-N-C catalyst via surfactant modified strategy for efficient electrocatalytic CO2 to CO

Recently, Ni, N-doped carbon (Ni-N-C) electrocatalysts synthesized using metal-organic frameworks (MOFs) as templates have demonstrated attractive catalytic performances in the CO2 reduction reaction (CO2RR). However, most of the reported preparations of MOFs-based precursors are carried out in organic solvents, and the resulting Ni-N-C materials have relatively low metal loadings and mainly exhibit microporous structures, which is unfavorable for the mass transport. Herein, Ni, N-doped meso-microporous carbon electrocatalysts with a range of Ni loadings (M-Ni-N-C-x/CNTs) were prepared by the pyrolysis of MOFs-based precursors synthesized in aqueous solution using the surfactant cetyltrimethylammonium bromide (CTAB) as a modifier to promote the adsorption of Ni2+ ions and the formation of mesopores. Owing to the unique morphology, porous structure and high contents of Ni-Nx sites and pyrrolic-N, the optimal catalyst (M-Ni-N-C-2/CNTs) shows superior electrocatalytic activity for the CO2RR with a maximum CO Faradaic efficiency (FECO) of 98 % at-0.7 V vs. reversible hydrogen electrode (RHE), and the FECO can reach over 80 % in a wide potential range of-0.5 to-1.0 V vs. RHE. This work develops a facile and environmentally friendly strategy to obtain high-performance and low-cost transition metal-nitrogen-doped porous carbon electrocatalysts for the CO2RR.(c) 2022 Elsevier Inc. All rights reserved.