Ambient-Temperature Reductive Amination of 5-Hydroxymethylfurfural Over Al2O3-Supported Carbon-Doped Nickel Catalyst

Graphical Reductive amination : Highly active and stable alumina-supported carbon-doped Ni nanoparticles are fabricated via a facile one-step pyrolysis-reduction strategy and achieve the reductive amination of 5-hydroxymethylfurfural into primary amine with ammonia and hydrogen at ambient temperature. An efficient catalytic system for the conversion of 5-hydroxymethylfurfural (HMF) into N-containing compounds over low-cost non-noble-metal catalysts is preferable, but it is challenging to reach high conversion and selectivity under mild conditions. Herein, an Al 2 O 3 -supported carbon-doped Ni catalyst was obtained via the direct pyrolysis-reduction of a mixture of Ni 3 (BTC) 2 ⋅ 12H 2 O and Al 2 O 3 , generating stable Ni 0 species due to the presence of carbon residue. A high yield of 96 % was observed in the reductive amination of HMF into 5-hydroxymethyl furfurylamine (HMFA) with ammonia and hydrogen at ambient temperature. The catalyst was recyclable and could be applied to the ambient-temperature synthesis of HMF-based secondary/tertiary amines and other biomass-derived amines from the carbonyl compounds. The significant performance was attributable to the synergistic effect of Ni 0 species and acidic property of the support Al 2 O 3 , which promoted the selective ammonolysis of the imine intermediate while inhibiting the potential side reaction of over-hydrogenation.