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 Cuδ+ (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.