Chlorine-Induced Dangling Nitrogen-Bridged Dual-Atom Iron Catalyst for Highly Efficient Oxygen Reduction

Dual-atom catalysts (DACs) are regarded as promising electrocatalysts owing to their abundant active sites and tunable electronic structures, whereas precisely controlling diatomic-site configurations for optimal performance remains challenging. Herein, we precisely engineer a Cl-induced dangling N-bridged dual-atom Fe catalyst (Fe₂NC-Cl), where the Cl introduction results in an out-of-plane dangling N-bridge to the di-Fe sites, mitigating the steric hindrance for reactants, and a strategic modulation of the d-band center of Fe sites, optimizing the adsorption-desorption equilibrium of oxygen-containing intermediates, thereby leading to a lower overpotential. The Fe₂NC-Cl catalyst achieves an exceptional oxygen reduction reaction (ORR) activity, exhibiting a half-wave potential of 0.924 V with minimal potential decay (0.067 μV per cycle). When integrated into quasi-solid-state zinc-air battery, it delivers a remarkable power density of 231 mW cm^-2 at 25 °C and maintains 82 mW cm^-2 at -40 °C, alongside stable operation for 2400 h (14400 cycles). This work underscores the critical role of synergistic geometric-electronic engineering in breaking the activity-stability trade-off, providing a universal design paradigm for high-performance electrocatalysts.