Selective reduction of adiponitrile to ?-aminocapronitrile on a nickel boride catalyst

Abstract

Listen

Translate article

1. The hydrogenation of adiponitrile to e -aminocapronitrile on a nickel boride catalyst and on skeletal nickel with titanium added was investigated. With an increase in the amount of titanium in the skeletal nickel catalyst, the selectivity of the latter increased. 2. The dinitrile was hydrogenated selectively to the aminonitrile on the nickel boride catalyst: 50–60% of the aminonitrile and only 2–5% of the diamine were formed under the optimal conditions. 3. The reason for the incomplete conversion of the dinitrile to the aminonitrile under half-hydrogenation conditions is adsorption displacement of the dinitrile by the aminonitrile. 4. In the hydrogenation of the dinitrile, cyclohexamethyleneimine is formed during the second stage of the process, while the formation of bishexamethylenetriamine increases appreciably when the dinitrile is hydrogenated in a mixture with hexamethylenediamine. As with other catalysts, ammonia suppresses the formation of both secondary amines. These facts confirm the aldimine mechanism for the hydrogenation of the dinitrile