FeNi Dual‐Metal Dimer Embedded in Nitrogen‐Doped Graphene for Enhanced Oxygen Reduction Catalysis: A Density Functional Theory Study

Developing highly effective single‐atom catalysts for oxygen reduction reaction (ORR) is critical to improve fuel cell efficiency. Hence, this study systematically investigates ORR performance of single‐metal (FeN4‐G, NiN4‐G) and dual‐metal (FeNiN3‐G) catalysts embedded in nitrogen‐doped graphene through density functional theory (DFT) calculations. Through analysis of ORR intermediates adsorption on M‐N‐C surfaces, the Gibbs free energy changes, density of states, and electron transfer profiles of catalytic systems are investigated. DFT calculations reveal that while the over‐binding of FeN4‐G and intermediates impedes desorption kinetics and weak interactions of NiN4‐G favor the less efficient 2e− pathway, FeNiN3‐G addresses these limitations through synergistic Fe‐Ni electronic coupling. By optimizing d‐band alignment and charge redistribution, FeNiN3‐G lowers the rate‐determining step energy barrier and reduces overpotential. Moreover, the dual‐metal configuration promotes selective 4e− ORR via efficient OO bond cleavage. This work provides mechanistic insights for designing high‐efficiency M‐N‐C electrocatalysts for energy conversion technologies.