Durable and highly active oxygen electrocatalysts are crucial to the large-scale application of rechargeable zinc-air batteries. Here we utilize the N4 unit in phthalocyanine molecule to trap the tungsten atoms scratched off from the tungsten carbide milling balls and place the obtained W-N4 unit adjacent to the Fe-N4 units from iron (Ⅱ) phthalocyanine, resulting in highly active Fe-N4/W-N4 diatomic sites with well-pronounced 3d-5d hybrid for efficient and durable oxygen electrocatalysis. The electron distribution of the Fe-N4 site is optimized by the neighboring W-N4 site, which facilitates the O2 activation and the desorption of *OH and enhances the catalytic activity of the Fe-N4 site. Meanwhile, the unsaturated 5 d orbitals and tunable valence of the W atoms could modulate the electronic state of the Fe species, prevent leaching, and further enhance the catalytic stability. The resulting zinc-air battery with Fe,W-N-C air cathode exhibits notable cycling stability and repeatability for over 10,000 h. This enhanced stability highlights the possibility of developing 5 d metal-boosted 3 d metal active sites for the fabrication of efficient oxygen electrocatalysts and stable zinc-air batteries.
Li et al. (Fri,) studied this question.