Effect of Metal–Metal Distance on the Performance of Dual‐Atom Catalysts for the Oxygen Reduction Reaction: A Density Functional Theory and Micro‐kinetics Study

Abstract Dual‐atom catalysts (DACs) display excellent activity for the oxygen reduction reaction (ORR). The dual‐metal configuration allows for synergistic interactions and tailored adsorption of key intermediates, thereby breaking traditional *OH–*OOH scaling relations and enabling dissociative O2 activation pathways. Recent studies suggest that the metal–metal (M–M) distance within DACs critically influences their electronic structure and catalytic behavior; however, a deep understanding of M–M distance effects on ORR thermodynamics and kinetics is presently lacking. Herein, density functional theory (DFT) calculations and microkinetic modeling are performed on 108 DACs with varied M–M distances (2.2–3.5 Å). Moderate M–M distances (≈3 Å) are found to weaken *OH binding, lower the *OH–*OOH scaling slope, and promote bridging O2 adsorption for facile dissociation. The dissociative pathway lowered the effective scaling relation from ≈3.2 to 2.72 eV, approaching the theoretical value of 2.46 eV. Micro‐kinetic simulations identified O2 activation as the rate‐determining step during ORR, with DACs possessing a M–M distance ≈3 Å exhibiting the highest turnover frequencies, due the effective balancing of active‐site availability and O2 activation efficiency. These findings highlight the key role of M–M distance in controlling ORR activity, guiding the design of next‐generation DACs with improved efficiency.