Universal Boron-Doped Nickel Nanocatalyst for Selective Amination and Hydrogenation under Mild Conditions

Catalytic reductions mediated by molecular hydrogen form a foundational pillar of synthetic organic chemistry and the chemical industry. However, such processes often rely on expensive catalysts and procedures, underscoring the urgent need for low-carbon and atom-economic alternatives. Development of robust heterogeneous catalysts based on earth-abundant, non-noble metals is, therefore, highly desirable. Herein, we report a highly active boron (B)-doped nickel nanocatalyst supported on TiO2, which demonstrates good performance in facilitating both reductive amination and hydrogenation reactions under mild conditions. This catalyst enables the following key transformations: (1) conversion of carbonyl compounds to amines, as well as nitroarenes to anilines; (2) selective hydrogenation of N-heterocycles and carbon–oxygen bonds; and (3) reduction of CO2 to methanol (MeOH) with an amine–alcohol system via a one-pot, one-step strategy. The optimized Ni-BPA@TiO2-800 catalyst exhibits stable reusability, maintaining great activity over five consecutive cycles without discernible loss. To unravel the mechanism behind its enhanced performance, systematic characterizations were conducted, revealing that B doping, owing to its electron-deficient nature and vacant p-orbitals, modulates the electronic structure of the nickel surface by withdrawing the electron density from Ni sites, which thermodynamically favors the stabilization of the metallic Ni0 state. H2-DRIFT and H2-D2 isotope exchange experiments demonstrate that B incorporation enhances the adsorption of hydrogen molecules at the metallic Ni sites and promotes their heterolytic cleavage on the catalyst surface, which facilitates effective hydrogenation pathways. This work demonstrates the utility of heteroatom doping in tuning non-noble metal catalysts and offers a promising protocol for designing efficient and general hydrogenation systems.