Hydrogenation of Aliphatic Nitriles on Raney Nickel: Influence of Parent Alloys and Dopes on Activity and Selectivity

Cr and Fe doped Raney nickel catalysts were prepared by alkali leaching of intermetallic alloys, Ni40Al60 or Ni25Al75 being the parent alloys. The selective hydrogenation of valeronitrile to the corresponding primary amine was performed in cyclohexane using a stirred autoclave. The increase in initial activity of the doped catalysts is attributed to the presence of oxides at the surface of the catalyst. The improvement in selectivity with doping is mainly explained by a decrease of the rate of hydrogenation of the intermediate secondary imine, thus favoring reverse reactions.