Fe, P Heteronuclear Catalytic Pairs with Hydrogen Bonding Regulated the Oxygen Reduction Reaction Kinetics for an Ultrastable Oxygen Depolarized Cathode

The rational design of efficient oxygen reduction reaction (ORR) catalysts with maximized atom utilization is essential for advancing the oxygen depolarized cathode technology. Here, we report atomically dispersed Fe, P heteronuclear catalytic pairs on hierarchical porous carbon, in which the hydrogen bond between Fe, P catalytic pairs and ORR intermediates significantly enhances the adsorption/desorption kinetics and lowers the rate-determining step barrier of OH* desorption. Thus, Fe,P/HPC delivers an alkaline ORR performance with a half-wave potential (E1/2) of 0.92 V and retains ∼90% of the initial activity even after 150 h operation. In addition, Fe,P/HPC achieves an E1/2 of 0.74 V in 0.1 M HClO₄. The Fe,P/HPC-based aqueous Zn-air battery (A-ZAB) achieves a high power density of 262 mW cm⁻² and exhibits enhanced stability, sustaining a minimal voltage gap over 2800 h of constant-current cycling. Moreover, the quasi-solid-state Zn-air battery (QSS-ZAB) delivers a large open-circuit voltage of 1.52 V, while maintaining a cycling stability for over 95 h at 0.5, 1, and 2 mA cm⁻², respectively. In the chlor-alkali process, the Fe,P/HPC||RuO₂ electrolyzer enables a large current density of 300 mA cm⁻² at 1.66 V and maintains stability over 110 h. The present work pioneers the designing and construction of atomic-level heteronuclear catalysts for practical and durable cathode.