| Summary: | A series of Ni/Al<sub>2</sub>O<sub>3</sub>, Ni/K<sub>2</sub>O-Al<sub>2</sub>O<sub>3</sub> and Ni/La<sub>2</sub>O<sub>3</sub>-K<sub>2</sub>O-Al<sub>2</sub>O<sub>3</sub> catalysts that possess high activities for partial hydrogenation of adiponitrile to 6-aminocapronitrile has been successfully synthesized by the impregnation method. The catalytic performance was investigated under atmospheric pressure and in the absence of ammonia and a significant enhancement in the activity after the introduction of potassium oxide and lanthana was observed. Aiming to study the influence of K<sub>2</sub>O and La<sub>2</sub>O<sub>3</sub> promoters on the physicochemical properties, we characterized the catalysts by N<sub>2</sub> adsorption/desorption, XRD, H<sub>2</sub>-TPR, H<sub>2</sub>-chemisorption, H<sub>2</sub>-TPD and TEM techniques. A combination of XRD, TEM and H<sub>2</sub>-chemisorption showed that Ni<sup>0</sup> particles with a higher dispersion are obtained after the addition of La<sub>2</sub>O<sub>3</sub>. Compared with the Ni/Al<sub>2</sub>O<sub>3</sub> catalyst, the Ni/La<sub>2</sub>O<sub>3</sub>-K<sub>2</sub>O-Al<sub>2</sub>O<sub>3</sub> catalyst with an appropriate amount of promoter enjoys a more catalyst surface alkalescence, enhances the electronic density of nickel and higher dispersion of nickel and exhibits higher activity and 6-aminocapronitrile selectivity than Ni/α-Al<sub>2</sub>O<sub>3</sub> during the hydrogenation of adiponitrile in the absence of ammonia, i.e., K<sub>2</sub>O and La<sub>2</sub>O<sub>3</sub> improved the performance of the nickel-based catalyst.
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