Efficient synthesis of tetrahydrofurfurylamine via aqueous reductive amination of furfural with ammonia catalyzed by amorphous nickel boride

o address the reliance on noble metal catalysts and harsh reaction conditions in the synthesis of tetrahydrofurfurylamine, this study prepared an amorphous nickel boride catalyst (NiB-1) via the reduction of nickel salts with NaBH4 and applied it to the reductive amination of furfural with ammonia in an aqueous phase to synthesize tetrahydrofurfurylamine. The composition, structure, and physicochemical properties of the catalyst were systematically characterized using ICP-OES, XRD, BET, TEM, XPS, and H2-TPD. The results indicate that NiB-1 possesses an amorphous nanosheet-like hierarchical porous structure with abundant oxygen vacancies on the surface. The synergistic effect between Ni0 and surface NiO enables precise modulation of the electron density at the active sites, endowing the catalyst with excellent hydrogen activation capability and substrate adsorption performance. Under optimal reaction conditions (40 mg NiB-1, 120 °C, 2 MPa H2, 1 h), the conversion of furfural reached 99.9%, with a tetrahydrofurfurylamine yield of 99.0%. Moreover, the spent NiB-1 catalyst, after simple washing, maintained stable catalytic performance over five consecutive cycles. The NiB-1 catalyst developed in this study offers a green and efficient approach for the reductive amination of biomass-derived furfural to primary amines, demonstrating promising potential for industrial applications.