In Situ-Generated Co⁰-Co₃O₄/N-Doped Carbon Nanotubes Hybrids as Efficient and Chemoselective Catalysts for Hydrogenation of Nitroarenes

The earth-abundant nanohybrids Co⁰/Co₃O₄@N-doped carbon nanotubes were fabricated via an efficient thermal condensation of d-glucosamine hydrochloride, melamine, and Co(NO₃)₂·6H₂O. The hybrids furnish excellent catalytic activity and perfect chemoselectivity (>99%) for a wide range of substituted nitroarenes (21 examples) under relatively mild conditions. The high catalytic performance and durability is attributed to the synergistic effects between each component, the unique structure of graphene layers-coated Co⁰, and the electronic activation of doped nitrogen. Density functional calculations indicate that the inner Co⁰ core and N species on the carbon shell can significantly decrease the dissociation energies of H₂, giving evidence of the ability of carbon shell in the hybrids to enable H₂ activation. These results open up an avenue to design more powerful low-cost catalysts for industrial applications.