How can the Dual-atom Catalyst FeCo-NC Surpass Single-atom Catalysts Fe-NC/Co-NC in CO2RR? - CO Intermediate Assisted Promotion via a Synergistic Effect

Atomically dispersed catalysts are widely adopted in CO2 reduction reaction (CO2RR) due to maximal atomic utilization and high catalytic activity. Dual-atom catalysts (DACs), with more dispersed active sites and distinct electronic structures compared with single-atom catalysts (SACs), may exhibit diverse catalytic performance. Herein, the DAC FeCo-NC and SAC Fe-NC/Co-NC are employed as probes to explore DACs advantage in CO2RR. Results show that the moderate interaction between the dual-atom center and N coordination balances structural stability and catalytic activity. CO is the only product on Fe-NC/Co-NC, and the high limiting potentials from -1.22 to -1.67 V inhibit further reduction. FeCo-NC assisted with CO intermediate exhibits low limiting potentials of -0.64 V for both CH3OH and CH4, comparable to those on Cu-based catalysts. Under circumstance of applied potentials, CO2RR on FeCo-NC has greater advantages in yielding CH3OH and CH4 than that on Fe-NC/Co-NC, and hydrogen evolution reaction is severely inhibited. The intrinsic essence is that dual-atom center can provide large spin-polarization and multi-electron transfer capability, rendering CO intermediates as effective electronic and geometric modifiers in CO2RR. This work highlights FeCo-NC as a high-performance CO2RR catalyst toward deep-reduction C1 products and elucidates CO intermediate assisted promotion mechanism via a dual-atom synergistic effect.

Automated summary

Atomically dispersed catalysts, specifically dual-atom catalysts (DACs), have shown promising potential in CO2 reduction reaction (CO2RR). This study investigates the advantages of DACs in CO2RR through the use of FeCo-NC and Fe-NC/Co-NC catalysts. The results demonstrate that DACs have a balanced interaction between dual-atom centers and N coordination, leading to improved catalytic performance in the production of CH3OH and CH4 while inhibiting hydrogen evolution reaction.