Room-temperature synthesis of primary amines by selective hydrogenation of nitriles over ZnAlOx supported Ni catalysts

Selective hydrogenation of nitriles is a feasible route to synthesize primary amines. While highly desirable, conducting the synthesis under mild conditions is challenging. We report non-precious zinc and aluminum oxides supported Ni catalysts (Ni/ZnAlOx) facilely prepared by calcination and reduction of NiZnAl layered double hydroxide (LDH) precursors. The optimized Ni/ZnAlOx-600 catalyst demonstrates great activity towards the selective hydrogenation of nitriles to primary amines. Proper-size metallic nickel provides the hydrogenation centers, and the presence of Ni-Zn alloys indicates strong metal-support interactions, which can produce electron-deficient nickel species and enhances the chemisorption of the CN bonds on the catalyst surface. The introduction of Zinc provides strong Lewis acid sites which also contribute to the catalytic activity. Based on the catalyst characterizations and control experiments, a plausible mechanism is proposed. This catalyst shows good stability and is conducive to the transformation of a variety of aromatic and aliphatic substrates, demonstrating potential application prospects.