Pearl Necklace Fibrous Carbon Sharing Fe–N/Fe–P Dual Active Sites as Efficient Oxygen Reduction Catalyst in Broad Media and for Liquid/Solid‐State Rechargeable Zn–Air Battery

Optimized catalysts are attractive from the standpoint of energy storage and conversion. Herein, a pearl necklace fibrous carbon catalyst with Fe–N/Fe–P dual active sites (Fe–P/NHCF) is fabricated via carbonization–phosphidation of metal–organic framework (MOF)/polyacrylonitrile nanofibers. Benefiting from Fe–N/Fe–P doping‐induced active sites, accompanied by particular hierarchical porous merit and a 1D necklace network to facilitate the oxygen reduction reaction (ORR), it exhibits a half‐wave potential of 0.82 V in alkaline medium and outperforms commercial Pt/C in terms of stability in acid medium. Furthermore, a low voltage gap (1.04 V) is acquired in a liquid Zn–air battery with Fe–P/NHCF as the cathode. Meanwhile, the portable solid‐state Zn–air battery displays an open circuit voltage of 1.32 V and a power density of 42 mW cm −2 . This strategy puts forward a protocol to develop tailored geometry with dual active sites for ORR in alkaline/acid media, which is expected to promote devices of practical significance.