<p>Various metal nanoparticle catalysts (Ru, Rh, Pd, Ir, and Pt) were prepared via liquid-phase reduction and their activity was studied for selective hydrogenation of benzonitrile to corresponding secondary imine under mild conditions (3 bar H₂ and 30 °C). The Rh catalyst with particle size of 2.7 nm exhibited excellent activity for the hydrogenation of benzonitrile to secondary imine. The catalyst was reused and applied to transform various nitriles to corresponding secondary imines.</p>