Process for hydrogenation of unsaturated dinitriles

In a process for producing saturated diamines or dinitriles from an olefinically unsaturated dinitrile feedstock comprising the reaction product obtained by contacting under suitable reaction conditions for producing said unsaturated dinitrile reactants consisting essentially of at least one olefinically unsaturated mononitrile reactant and at least one monoadduct reaction product of an olefinic hydrocarbon compound and an olefinically unsaturated mononitrile compound wherein each said olefinically unsaturated mononitrile reactant and each said olefinically unsaturated mononitrile compound contain a cyano group attached to a carbon atom adjacent and doubly bonded to a carbon atoms which is attached to at least one hydrogen atom and each said olefinic hydrocarbon reactant and each said olefinic hydrocarbon compound have at least one olefinic linkage having joined thereto a carbon atom having at least one hydrogen atom attached thereto comprising subjecting the feedstock to suitable hydrogenation conditions in the presence of hydrogen and a suitable hydrogenation catalyst, the improvement comprising contacting the feedstock with a crystalline zeolite so as to extend the activity of said hydrogenation catalyst.