Boron Modified Cu/Al2O3 Catalysts for the Selective Reductive Amination of Levulinic Acid to N-Substituted Pyrrolidinones

Graphical Through a convenient impregnation method, highly-distributed and stable Cu nanoparticles were dispersed on the boron doped γ-Al 2 O 3 support, which catalyzed continuous reductive amination of levulinic acid to corresponding N-substituted pyrrolidinones. The reductive amination of biomass-derived levulinic acid (LA) to value-added N-substituted pyrrolidinones with amine and molecular hydrogen over heterogeneous catalyst represents an atom-economical and scalable route. In this paper, a series of boron doped Cu/Al 2 O 3 catalysts via kneading and impregnation method are developed for the continuous reductive amination of LA. Compared with Cu/Al 2 O 3 , Cu 10 /AlB 3 O catalyst exhibits greatly improved catalytic performance for this reaction at low operation temperature. Structure-property correlation investigations were performed with diverse characterization methods, and the results revealed that the excellent catalytic performance of boron doped Cu/Al 2 O 3 catalysts was mainly attributed to the synergistic effect of its well-dispersed Cu nanoparticles, appropriate surface Cu electronic state and surface acidic sites nearby. Besides, Cu 10 /AlB 3 O shows great stability during the reaction over 200 h. This work provides a low-cost, efficient and environmentally friendly heterogeneous catalytic system for the continuous production of N-substituted pyrrolidinones.