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Fe–N–C single-atomic metal site catalysts (SACs) have garnered tremendous interest in the oxygen reduction reaction (ORR) to substitute Pt-based catalysts in proton exchange membrane fuel cells. Nowadays, efforts have been devoted to modulating the electronic structure of metal single-atomic sites for enhancing the catalytic activities of Fe–N–C SACs, like doping heteroatoms to modulate the electronic structure of the Fe–N_x active center. However, most strategies use uncontrolled long-range interactions with heteroatoms on the Fe–N_x substrate, and thus the effect may not precisely control near-range coordinated interactions. Herein, the chlorine (Cl) is used to adjust the Fe–N_x active center via a near-range coordinated interaction. The synthesized FeN₄Cl SAC likely contains the FeN₄Cl active sites in the carbon matrix. The additional Fe–Cl coordination improves the instrinsic ORR activity compared with …