Constructing Nitrogen-Coordinated Single Atom Catalysts via Bond-Plucking Strategy for Oxidation of Benzene

Single-atom catalysts (SACs) with nitrogen-coordinated active centers feature unique electronic and geometric structures and thus show high catalytic activity for various industrial reactions. Searching for operable synthesis protocols to accurately devise SACs is vital but remains challenging because commonly used high-temperature pyrolysis always causes unpredictable structural changes and inhomogeneous single-atom sites. Herein, a mild bond-plucking strategy is reported to construct atomically dispersed Cu supported on graphene-liked C₃N₄ (g-C₃N₄) under lower than 100 °C, and Cu foam is used as the source of metal. When g-C₃N₄ closely coats the surface of Cu foam, Cu⁰ atoms on Cu foam transfer electrons to nitrogen on g-C₃N₄ due to the strong Lewis acbase interaction, simultaneously forming Cu^δ+ (0 < δ < 2) and Cu─N bonds. Subsequently, g-C₃N₄ nanosheets are exfoliated out from the surface of Cu foam, eventually obtaining a well-defined Cu single atoms/g-C₃N₄ (Cu SAs/g-C₃N₄) catalyst with atomically dispersed Cu-N₃ moieties. Cu SAs/g-C₃N₄ serves as a highly effective and durable catalyst toward the oxidation of benzene to phenol at 60 °C, with a conversion of 65.1% and selectivity of 97.6% after 12 h. The findings pave a new way to construct well-defined SACs at low costs, promoting large-scale production and industrial application.