Tuning the coordination number of Fe single atoms for the efficient reduction of CO2†
CO2 electroreduction into valuable products holds great promise for energy supply and environmental remediation but remains a challenge due to the lack of high-performance electrocatalysts. Herein, we developed an efficient strategy to prepare highly active Fe single-atom catalysts (Fe–N5/Fe–N6) by tuning the coordination number of Fe with N towards CO2 electroreduction. The faradaic efficiency of CO for Fe–N5 exceeded 90% ranging from −0.35 to −0.65 V versus the reversible hydrogen electrode (vs. RHE) towards CO2 electroreduction. The turnover frequency of CO for Fe–N5 reached 5006 h−1 at −1.05 V vs. RHE, which was 3.8 times that (1324 h−1) of Fe–N6. Besides, CO was generated at an overpotential as low as 50 mV over Fe–N5, smaller than that (90 mV) over Fe–N6. Density functional theory calculations demonstrated that Fe–N5 facilitated the adsorption and activation of CO2 to form the *COOH intermediate, thus leading to superior selectivity and activity for CO2 electroreduction.
- This article is part of the themed collection: CO2 Utilisation