Remodified Ni/Al₂O₃ Catalysts for the Gas-Phase Reductive Amination of 1‑Octanol: Reconfiguration of Acid-Base Sites...

In industrial applications, the amination of long-chain fatty alcohols to synthesize fatty amines still faces challenges such as unstable reaction rates and low product yields. Therefore, developing a catalyst for the amination of long-chain fatty alcohols that achieves high yields remains a significant challenge. Herein, we report that a series of Ni-Re/Al₂O₃ catalysts were synthesized and characterized for the continuous gas-phase reductive amination of 1-octanol with ammonia under atmospheric pressure. The results indicate that the presence of Re not only promotes hydrogen spillover and accelerates the reduction of Ni species but also weakens Ni-O-Al interactions and reconstructs the surface acid-base properties. The resulting balanced distribution of weakly basic, moderately basic, and strongly basic sites regulates primary amine selectivity, with yield exhibiting a volcano-shaped relationship with Re content. Under the optimal conditions, the Ni-2Re/Al₂O₃ catalyst achieves 99.5% conversion and 64% monoamine selectivity. This study reveals the synergistic effect of Re in regulating metal-support interactions and acid-base sites, which provides a rational design strategy for non-noble catalysts in the reductive amination of long-chain alcohols.