Boosting Amination of 1-Octanol to 1-Octylamine via Metal-Metal Oxide Interactions in NixFe1/Al2O3 Catalysts

Graphical Octylamine synthesis : Ni x Fe 1 /Al 2 O 3 was used as catalyst for 1-octanol amination and provided the highest yield among the reported nonprecious metal catalysts. The generation of Ni−FeO x interactions provided sufficient Fe 2+ /Fe 3+ −O 2− sites for the activation of 1-octanol. Meanwhile, the cooperation between Ni site and Lewis acid-base pairs significantly enhanced the amination of 1-octanol to 1-octylamine. The synthesis of 1-octylamine, a primary platform molecule, remained a great challenge in catalysis. In this work, Ni x Fe 1 /Al 2 O 3 was used for direct amination of 1-octanol to 1-octylamine. Catalyst evaluation indicated that the promotion effect of Fe/Ni ratio on the catalytic amination activity followed a volcano curve while the selectivity to 1-octylamine was positively correlated with the Fe loading. Compared with the Ni/Al 2 O 3 catalyst, the amination activity was increased by 2.8 times by optimizing the Fe/Ni ratio to 0.33, and the selectivity to 1-octylamine was increased from 84.0 % to 96.3 % when increasing the Fe/Ni ratio from 0 to 1. Based on catalyst characterizations, the good performance of Ni x Fe 1 /Al 2 O 3 was ascribed to the combined modification effect of the NiFe alloy and Ni−FeO x interface. The FeO x species enriched on the Ni particle surface provided sufficient Fe 2+ /Fe 3+ −O 2− sites for the activation of 1-octanol, and the cooperation between Ni sites and Lewis acid-base pairs enhanced the amination of 1-octanol to 1-octylamine. This work sheds new light on the design of Ni-based catalysts without using a noble metal for primary amine preparation.