Regulating Adsorption of Intermediates via the Sulfur Modulating Dual-Atomic Sites for Boosting CO₂RR

The formation of dual-atom catalysts or heteroatom ligand modulation is the most promising strategy for optimizing single–atom catalysts (SACs) for the more efficient conversion of CO2 to valuable chemicals. However, heteroatom ligands introduced into the dual-atomic sites are expected but still under-explored. In this study, a dual-atom Fe–Ni pair electrocatalyst with N– and S–coordination in porous carbon nanosheets was conceptually predicted for electrocatalytic CO2 reduction to CO (CO2RR). In contrast to SACs and traditional diatomic catalysts (DACs), joined S–coordination can balance the cooperative activities of Fe and Ni sites, making the CO2 adsorption configuration bidentate at both Fe–Ni sites. This regulation leads to a substantial change in CO* adsorption from Fe to Ni sites, facilitating CO desorption and boosting the electrocatalytic CO2RR. Experimental results demonstrate that the obtained FeNi–NSC catalyst achieves high selectivity with the Faradaic efficiencies for CO of 96.1%, and a remarkable activity with the turnover frequency of 6526.9 h–1 at −1.0 V, which were over 4.5 and 2.5 times of those from the single Fe or Ni sites. This work gives us insight into designing highly effective catalysts guided by theoretical calculation.