Modulating intermediate coverage of single-atom catalyst for kinetics-boosted CO2 electroreduction in membrane electrode assembly

Developing high-efficiency electrocatalysts with low overpotential and industrial-level current density is crucial to CO2 electroreduction (CO2ER). However, the poor modulating of intermediate *CO effective coverage results in low selectivity of target product. Herein, a feasible strategy to modulate *CO effective coverage on isolated nickel sites through S-coordinated doping (Ni-NSC) is reported. Incorporation of S species in the coordination of Ni-NSC leads to a low-coordination state of center Ni atom, which enhances hybridization of the d band with the 2 pi* orbital of CO, improving CO coverage. As a result, Ni-NSC reaches an industrial-level current density of over 280 mA cm -2 in a membrane electrode assembly device, and realizes the maximum FECO above 95 %. Control experiments and characterizations reveal that the monovalent Ni atomic center in the Ni-NSC after S doping promotes the formation of reactive intermediate *COLFB and improves *CO effective coverage, thus boosting the CO2ER kinetics.