Circumventing Radical Generation on Fe-V Atomic Pair Catalyst for Robust Oxygen Reduction and Zinc-Air Batteries

Iron-nitrogen-carbon (Fe-N-C) catalysts are considered the most active platinum-free alternative for oxygen reduction reaction (ORR), yet the generated reactive oxygen species (ROS) from general mechanistic pathway rapidly impair the ORR activity and stability of Fe-N-C. Herein, we establish and report an ORR pathway-switching strategy to circumvent ROS generation and fundamentally improve the activity and stability of Fe-N-C via DFT guided catalyst design. The constructed Fe-V atomic pair catalyst (Fe₁V₁-NC) with N₂Fe-N₂-VN₂ configuration enables side-on adsorption of O₂ and subsequent direct-breaking of the O═O bond to form O*, thereby avoiding the formation of ROS radicals. Importantly, there is intersite electron interaction between FeN₄ and VN₄, which further boosts the ORR activity. Consequently, Fe₁V₁-NC exhibits outstanding ORR activity with onset and half-wave (E_1/2) potentials at 1.02 and 0.89 V versus RHE, respectively, in 0.1 M KOH. Record-high stability is achieved on Fe₁V₁-NC with a minimal decay in E_1/2 by 16 mV over 50000 cycles, surpassing Fe-N-C counterpart and most of the catalysts reported to date. The Fe₁V₁-NC-based zinc-air battery reported here demonstrates exceptional durability up to 400 h at 10 mA·cm^-2. This work identifies the intrinsic correlation between ORR pathway, activity, and stability, advancing development of stable catalytic systems.