Selective Cleavage of Cu─N Bonds Reshaped Asymmetric Dicopper Centers and Surface Polarity for Enhanced Biomimetic Oxidation

ABSTRACT

Efficient O ₂ activation at dicopper sites was often stifled by the symmetric coordination configuration of the active center and a long‐overlooked interface shielding‐triggered mass‐transfer barrier dictated by the surface polarity of the catalyst. Herein, we reported a phosphorus‐mediated chemical editing strategy to simultaneously overcome these constraints. By utilizing Hard and Soft Acids and Bases‐guided selective cleavage of partial Cu─N bonds, we transformed a Cu‐based precursor with the N ₄ Cu‐CuN ₄ S configuration into an asymmetric low‐coordinated N ₂ Cu‐CuN ₂ S center. Such an asymmetric reconfiguration not only induced a pivotal reversal in surface polarity to reshape the catalytic interface from a dense cation‐rich inner Helmholtz plane to a loose O ₂ ‐permeable outer Helmholtz plane, thereby facilitating O ₂ diffusion and enrichment, but also upshifted the d‐band center to strengthen intrinsic O ₂ adsorption and polarization. This dual regulation significantly accelerated the generation of reactive oxygen species, endowing the N ₂ Cu‐CuN ₂ S site with superior 4e oxidase‐like activity over its N ₄ Cu‐CuN ₄ S counterpart and most previous Cu‐based catalysts with symmetric configurations. Leveraging the high activity and thiophilic nature of this N ₂ Cu‐CuN ₂ S site, we developed a glutathione sensor with a 0.383 ppm detection limit. This work offered a selective editing avenue to engineer high‐performance biomimetic catalysts with precise control over both the molecular and interfacial environment for catalysis and biosensing.