Nanoparticles of rhodium embedded in polyvinylpyrrolidone (PVP), as catalyst, were investigated in the hydrogenation of different substrates (benzene, phenylacetylene, norbornene, quinoline, adiponitrile). The solid was used as a heterogeneous catalyst or as a soluble heterogeneous catalyst in biphasic conditions (liquid/liquid) when the catalyst was dissolved in water. In both cases., the kinetics of the catalytic reaction were found to be zero-order in respect to the substrate and first-order with respect to hydrogen and catalyst. The higher hydrogenation reaction rate was found for benzene by using biphasic conditions. The [Rh-PVP] catalyst has shown an efficient activity for the catalytic hydrogenation of norbornene, quinoline and adiponitrile into norbornane, tetrahydroquinoline and 6-aminocapronitrile. (C) 2002 Elsevier Science B.V. All rights reserved.