Carbon-supported palladium catalysts were prepared by ion-exchange and precipitation/deposition methods on various activated carbons. Pd/carbon catalysts with Pd particles ranging from 1.5 to 10 nm were thus obtained. The liquid phase hydrogenation of c,t,t-1,5,9-cyclododecatriene was carried out on these catalysts. A structure-sensitivity was observed with a decrease of TOF on smallest Pd particles. The highest yield to half-hydrogenated cyclododecene was observed on large Pd particles (similar to 10 nm). (c) 2006 Elsevier B.V. All rights reserved.