Nickel dual-atom sites for electrochemical carbon dioxide reduction

Dual-atom catalysts, combining single-atom catalysts and metal alloys, are promising electrocatalysts for CO2 reduction but are limited by sluggish CO2 reduction kinetics and ill-defined dual-atom sites. Here, we develop a catalyst of Ni dual-atom sites via in situ conversion of nanoparticles into dual atoms. We achieve efficient electrocatalytic CO2 reduction on Ni dual-atom catalysts with a CO partial current density up to ~1 A cm−2 and turnover frequency of 77,500 h−1 at >99% Faradaic efficiency. In situ X-ray absorption and theoretical calculations reveal that during the catalytic process the Ni dual-atom sites trigger the adsorption of hydroxyl (OHad), forming electron-rich active centres that endow a moderate reaction kinetic barrier of *COOH formation and *CO desorption. The resultant catalytic microenvironment enables expedited kinetics compared with either the kinetics of bare dual-atom sites or OHad regulated single-atom sites.