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.