Atomically Dispersed Dual‐Metal Site Catalysts for Enhanced CO2 Reduction: Mechanistic Insight into Active Site Structures.

Carbon‐supported nitrogen‐coordinated single‐metal site catalysts (i.e., M−N−C, M: Fe, Co, or Ni) are active for the electrochemical CO2 reduction reaction (CO2RR) to CO. Further improving their intrinsic activity and selectivity by tuning their N−M bond structures and coordination is limited. Herein, we expand the coordination environments of M−N−C catalysts by designing dual‐metal active sites. The Ni‐Fe catalyst exhibited the most efficient CO2RR activity and promising stability compared to other combinations. Advanced structural characterization and theoretical prediction suggest that the most active N‐coordinated dual‐metal site configurations are 2N‐bridged (Fe‐Ni)N6, in which FeN4 and NiN4 moieties are shared with two N atoms. Two metals (i.e., Fe and Ni) in the dual‐metal site likely generate a synergy to enable more optimal *COOH adsorption and *CO desorption than single‐metal sites (FeN4 or NiN4) with improved intrinsic catalytic activity and selectivity. [ABSTRACT FROM AUTHOR]