Positively charged nickel-sulfur dual sites for efficient CO2 electroreduction reaction

Abstract

Electrochemical CO2 reduction (CO2RR) into chemicals and fuels has gained great interest, but is subjected to low current density and poor product selectivity. Here a theory-guided design of sulfur-doped single nickel atom catalyst (Ni-SAC/SNC) with the optimal Ni-S dual active configuration was present for efficient CO2RR. Experiments combined with theory verified that the positively charged Ni-S dual sites drastically promoted the electronic localization of Ni center, which improved the stabilization of key COOH* intermediate and thus boosted CO production on Ni. This catalyst exhibited a high CO Faradaic efficiency of ∼98% and a current density of ∼32.5 mA cm−2 at a low overpotential of 620 mV, which exceeded most of single-atom electrocatalysts. This work offers atomic-level insights into the correlation between the electronic density of atomic sites and CO2RR performance, promoting the theory-guided rational design of efficient catalysts.