Hydrogenation of dodecanenitrile over Raney type and supported group VIII metal catalysts.: Effect of metal on selectivity

Supported Co, Ni, Ru, Rh, Pd and Pt as well as Raney Ni and Co catalysts were used for the hydrogenation of dodecanenitrile to amines in stirred SS autoclaves both in cyclohexane and without a solvent. The reaction temperature and the hydrogen pressure were varied between 90-140 degrees C and 10-80 bar, respectively. Over Ni catalysts NH3 and/or a base modifier suppressed the formation of secondary amine. High selectivity (93-98%) to primary amine was obtained on Raney nickel, Ni/Al2O3 and Ru/Al2O3 catalysts at complete nitrile conversion. With respect to the effect of metal supported on alumina the selectivity of dodecylamine decreased in the order: Co similar to Ni similar to Ru > Rh > Pd > Pt. The difference between Group VIII metals in selectivity can be explained by the electronic properties of d-band of metals. High selectivity to primary amine was achieved on base modified Raney Ni even in the absence of NH3.