Stepwise Anchoring of Atomically Dispersed Fe‐Fe Diatomic Sites via a Prussian Blue Analogue Route for Advanced Oxygen Reduction in Zinc‐Air Batteries

ABSTRACT Dual‐atom catalysts (DACs) outperform single‐atom catalysts (SACs) via interatomic electronic modulation of active sites, yet accurate fabrication of diatomic structures restricts their mechanistic research. Herein, we fabricate a Fe‐Fe homonuclear DAC (Fe (CN)6 ‐Fe‐NC) through strong coordination between ferrocyanide and unsaturated Fe sites on Fe‐ZIF‐NC inspired by Prussian blue chemistry. A two‐step synthetic route preloads Fe ions in ZIF‐8 before introducing ferrocyanide, which precisely forms Fe‐Fe dual sites and avoids Fe cluster aggregation. The paired Fe atoms deliver two synergistic effects toward the oxygen reduction reaction (ORR): bridging O 2 adsorption weakens O─O bonds to reduce dissociation barriers, and intermetallic electron tuning optimizes intermediate desorption. The catalyst achieves a remarkable half‐wave potential of 0.91 V, surpassing commercial Pt/C (0.84 V). Assembled as air cathodes, liquid and flexible Zn‐air batteries reach peak power densities of 235.9 and 163 mW cm −2 both exceeding Pt/C counterparts. This coordination engineering strategy enables controllable homonuclear diatomic construction and reveals promising prospects of DACs for advanced energy devices.