Single-atom catalysts with bimetallic centers for high-performance electrochemical CO2 reduction

Abstract: The electrochemical CO2 reduction reaction (CO2RR) is a promising approach to alleviating global warming while concomitantly producing synthesis gas. Simultaneously achieving high current densities and tunable CO/H2 (syngas) ratios remains a highly desired yet difficult challenge. Herein, we developed a 3D carbon-based material exhibiting bimetallic centers (NiNC and FeNC) with synergistic effects for the CO2RR. The molar CO/H2 ratio (∼1:3 to ∼4:1) was altered by varying the configuration structures of the metal-N sites and tuning the applied potential for industrial applications of syngas. Density functional theory calculations verified these experimental results. Additionally, varying the configuration structures of bimetallic centers changed the rate-limiting steps of FePc@NiNC(+0.95?eV), NiNC/FeNC (+1.25?eV) and NiPc@FeNC (+1.37?eV) for CO2RR, while maintaining high catalytic activity with tunable syngas production. The reported materials system in this work represents a significant advancement of the CO2RR towards practical applications.