Electroreduction of Carbon Dioxide Driven by the Intrinsic Defects in the Carbon Plane of a Single Fe–N4 Site

Abstract Manipulating the in‐plane defects of metal–nitrogen–carbon catalysts to regulate the electroreduction reaction of CO 2 (CO 2 RR) remains a challenging task. Here, it is demonstrated that the activity of the intrinsic carbon defects can be dramatically improved through coupling with single‐atom Fe–N 4 sites. The resulting catalyst delivers a maximum CO Faradaic efficiency of 90% and a CO partial current density of 33 mA cm −2 in 0.1 m KHCO 3. The remarkable enhancements are maintained in concentrated electrolyte, endowing a rechargeable Zn–CO 2 battery with a high CO selectivity of 86.5% at 5 mA cm −2 . Further analysis suggests that the intrinsic defect is the active sites for CO 2 RR, instead of the Fe–N 4 center. Density functional theory calculations reveal that the Fe–N 4 coupled intrinsic defect exhibits a reduced energy barrier for CO 2 RR and suppresses the hydrogen evolution activity. The high intrinsic activity, coupled with fast electron‐transfer capability and abundant exposed active sites, induces excellent electrocatalytic performance.