Refining Asymmetric Low‐Coordinated Fe‐N₃ Motif to Boost Catalytic Ozonation Activity

Abstract In the quest to boost the intrinsic activity of single‐atom catalysts (SACs), optimizing the electronic properties of metal centers and maximizing active sites play a pivotal role. Here, a facile surface molten salt‐assisted approach for fabricating porous iron‐nitrogen‐carbon catalysts enriched with catalytically accessible single‐atom motifs is reported. Multiple characterization analyses prove that abundant intrinsic defects are generated at the edge sites, resulting in the formation of thermally stable unstitched Fe‐N₃ motif. Theoretical investigations unveil that the transition from Fe‐N₄ to Fe‐N₃ induces structural alteration, resulting in the convergence of Fe‐3d orbital energy to Fermi energy. The low‐coordinated Fe‐N₃ motif exhibits higher activation ability, reinforcing its interaction with O₃ and weakening the O‐O bond. This leads to a reduction in the reactivity of surface atomic oxygen barriers (O₃‐to‐*O/*OO), ultimately achieving efficient catalytic oxidation of methyl mercaptan and its intermediates, achieving performance 20‐fold higher than intact Fe‐N₄ catalysts and 625‐fold higher than commercial MnO₂. These findings present a comprehensive approach for synthesizing SACs with fully accessible active sites and boosted electronic configurations to advance catalytic ozonation activity.