Single-atom cobalt catalysts for chemoselective hydrogenation of nitroarenes to anilines

Single-atomic catalysts (SACs) caught considerable attention due to their unique structural properties, complete exposed active site, and 100% atom utilization efficiency with remarkable catalytic activity. Mesoporous single-atomic cobalt catalyst with Co-N₄ active sites was synthesized by using nitrogen-doped graphene derived from acrylonitrile. Single-atomic cobalt was observed by aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) in Co@Nx-C-800. Notably, the density functional theory (DFT) calculation and the extended X-ray absorption fine structures (EXAFS) fitting results indicate that the coordination structure of Co-N is four-coordinated. In this work, the practical hydrogenation of nitroarenes to anilines enabled by Co@Nx-C-800 was established with excellent yields and selectivity, which proved its advantages and potential applications.