Institution: | a Sous-unité Chimie des Matériaux Catalytiques, Laboratoire des Matériaux, Surfaces et Procédés Pour la Catalyse (LMSPC), ECPM-ULP, UMR 7515 du CNRS, 25, rue Becquerel, 67087 Strasbourg Cedex 2, France b Laboratoire de Chimie, d’Electronique et Photonique Moléculaires, ECPM-ULP, UPRES-A 7008 CNRS, 25, rue Becquerel, 67087 Strasbourg Cedex 2, France c Groupe Surface & Interface, IPCMS-ULP, UMR 7504 CNRS, 23, rue du Loess, 67037 Strasbourg Cedex, France |
Abstract: | Carbon nanofibers (CNFs) prepared by decomposition of ethane over a Ni/alumina catalyst, are used as support for palladium clusters. The carbon support displays a mean diameter of 40–50 nm, lengths up to several tens of micrometers, as highlighted by transmission electron microscopy (TEM) observations and a specific surface area of about 50 m2/g. The spheroidal palladium particles have a relatively homogeneous and sharp size distribution, centered at around 4 nm. This novel Pd/carbon nanofiber catalyst displays unusual catalytic properties and is successfully used in the selective hydrogenation of the C=C bond in cinnamaldehyde at a reaction temperature of around 80°C, under continuous hydrogen flowing at atmospheric pressure. The high performances of this novel catalyst in terms of efficiency and selectivity are, respectively, related to the inhibition of the mass-transfer processes over this non-porous material and to peculiar palladium–carbon interactions. It is concluded that the absence of microporosity in the carbon nanofibers favours both the high activity and selectivity which is confirmed by comparison with the commercially available high surface area charcoal supported palladium catalyst. |