Carbon support hydrogenation in Pd/C catalysts during reductive thermal treatment

Abstract The resistance of the Pd/C samples towards hydrogenation of the carbon support was studied in the temperature-programmed and isothermal regimes. Carbonaceous graphite-like material Sibunit was used as a carbon support. Pristine Sibunit was additionally graphitized via high temperature treatment (1900 °C) in an inert atmosphere. Both initial and graphitized supports were subjected to oxidative treatment in order to increase the amount of surface functional oxygen-containing groups. Palladium (1 wt%) was supported using an aqueous solution of H 2 PdCl 4 . All the samples were characterized by a low-temperature adsorption of nitrogen, transmission electron microscopy, and Raman spectroscopy. The graphitization procedure was found to decrease significantly the specific surface area of the support, while the oxidative treatment affects this parameter negligibly. Testing the Pd-containing samples in a hydrogen flow revealed the following order in accordance with amount of methane released: Pd/iSib » Pd/iSib-ox > Pd/gSib > Pd/gSib-ox.