Syngas evolution through CO2 electroreduction over sulfur-bridged electron deficient cobalt and nickel dual atom catalysts

Renewable-driven electrochemical reduction of CO 2 (CO 2 RR) to syngas is an attractive approach to achieve carbon neutrality. However, high current density at specific H 2 /CO molar ratios is challenging. Herein, a sulfur, nitrogen co-doped carbon supported Ni an Co dual-atom-system is designed as electrocatalyst to produce syngas from CO 2 RR. By regulating the molar ratio of Co and Ni in the dual atom system, H 2 /CO molar ratios of 1 and 2 that are typically suitable for a downstream Fischer-Tropsch synthesis process can be controlled in a wide current density range from 50 to 250 mA/cm 2 . This is attributed to the fact that single Ni sites are highly active for CO 2 RR to CO, while single Co sites are highly active for H 2 production. Moreover, experiments combined with theory confirm the presence of a sulfur-bridged Co and Ni moiety in the dual-atom system, and electrons are transferred from the Co and neighboring Ni sites to the bridged S atom. These electron deficient Co and Ni sites efficaciously balanced the adsorption strength of COOH* and H*, further facilitating syngas production without scarifying total current densities. This study provides a useful case for the fabrication of dual-atom catalysts with industrial relevant syngas production via CO 2 RR.