Atomically Tailored Fe-Dy Dual-Atom Sites With 3d-4f Orbital Coupling for Enhanced Bifunctional Oxygen...

Efficient bifunctional oxygen electrocatalysts are crucial for overcoming the high overpotentials and sluggish kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in rechargeable zinc-air batteries (ZABs). Iron-based single-atom catalysts exhibit promising ORR activity, however, their excessive adsorption of oxygen-containing intermediates, together with the scaling relationships between these intermediates, limits their bifunctional performance. Herein, a unique Fe-Dy dual-atom catalyst (FeDy-DAC) is constructed, leveraging the strong orbital coupling between Fe-3d and Dy-4f orbitals to precisely modulate the electronic structure of the Fe sites. This modulation effectively weakens the overly strong adsorption of oxygen-containing intermediates on Fe sites, facilitating ^*OH desorption. Meanwhile, the unique dual-site co-adsorption configuration of ^*O drives efficient O─O bond coupling, ultimately leading to a significant reduction in the rate-determining energy barriers of both ORR and OER. Therefore, FeDy-DAC exhibits outstanding bifunctional catalytic performance, with a high ORR half-wave potential of 0.90 V and a narrow ORR/OER potential gap of 0.68 V. Moreover, FeDy-DAC maintains stable operation for over 2500 h in ZABs, showcasing excellent long-term durability. This work provides a novel strategy and insights for high-performance bifunctional electrocatalyst design.