Asymmetry Spin‐Orbit of Single Iron Active Site Enhance Oxygen Reduction Reaction

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Asymmetric electron distribution of single‐atom catalysts (SAC) is an important means of regulating intrinsic catalytic activity. However, limited by synthetic preparation methods, understanding of the mechanism of asymmetrically coordinated single‐atom catalysis is restricted. In this study, leveraging the micropore confinement effect, nitrogen and phosphorus‐doped microporous carbon is used as a substrate to successfully anchor singly dispersed Fe atoms, constructing the asymmetrically coordinated single‐atom Fe site coordinated with N and P atoms (Fe‐SAs/NPC). The existence of the Fe‐N 3 P 1 site structure breaks the symmetry Fe‐N 4 in Fe‐SAs/NC, which would optimize the adsorption strength of intermediates. The resulting Fe‐SAs/NPC exhibits excellent ORR activity with a half‐wave potential of 0.91 V (0.1 m KOH), which is 40 mV higher than that of Fe‐SAs/NC (0.87 V). Combined with theoretical calculations, an in‐depth understanding of the asymmetric electronic configuration from the perspective of spin orbitals can enhance the electronic activity near the Fermi level and strengthen the adsorption of oxygen‐containing intermediates. This work provides new perspectives and ideas for understanding spin‐electronic behavior in catalytic processes. Furthermore, the Zn‐air battery constructed using Fe‐SAs/NPC exhibits a high power density of 187.7 mW cm −2 and a specific capacity of 819.6 mAh g Zn −1 at 10 mA cm −2 .