Boosting the Proton-coupled Electron Transfer via Fe-P Atomic Pair for Enhanced Electrochemical CO2 Reduction

Single-atom catalysts exhibit superior CO2-to-CO catalytic activity, but poor kinetics of proton-coupled electron transfer (PCET) steps still limit the overall performance toward the industrial scale. Here, we constructed a Fe-P atom paired catalyst onto nitrogen doped graphitic layer (Fe1/PNG) to accelerate PCET step. Fe1/PNG delivers an industrial CO current of 1 A with FECO over 90 % at 2.5 V in a membrane-electrode assembly, overperforming the CO current of Fe1/NG by more than 300 %. We also decrypted the synergistic effects of the P atom in the Fe-P atom pair using operando techniques and density functional theory, revealing that the P atom provides additional adsorption sites for accelerating water dissociation, boosting the hydrogenation of CO2, and enhancing the activity of CO2 reduction. This atom-pair catalytic strategy can modulate multiple reactants and intermediates to break through the inherent limitations of single-atom catalysts.

Automated summary

In this study, a Fe-P atom paired catalyst was constructed to accelerate the proton-coupled electron transfer (PCET) step and improve the catalytic activity of CO2-to-CO conversion. It was found that the P atom in the atom pair provided additional adsorption sites, accelerating water dissociation, boosting the hydrogenation of CO2, and enhancing the activity of CO2 reduction. This atom-pair catalytic strategy has the potential to overcome the inherent limitations of single-atom catalysts.