Characterization of Ru on Activated Carbon Catalysts Prepared by Supercritical Carbon Dioxide Impregnation

In this work, a novel method was reported for preparation of Ru/activated carbon (Ru/AC) catalysts. Supercritical carbon dioxide (SC CO2) was employed as medium for the impregnation of ACs with inorganometallic precursor of RuCl3. The Ru/AC catalysts displayed excellent activity for the catalytic hydrogenation of D-glucose. Selected Ru/AC catalysts were characterized by N2adsorption-desorption, TPR and TEM analysis. The results show that the order of effects on catalytic activity are supercritical temperature > supercritical pressure > amount of co-solvent > time of impregnation. The optimal supercritical parameters for preparing Ru/AC catalyst were 313 K, 8 MPa, 4 ml of methanol and 9 h, respectively. The highest reaction rate of hydrogenation reached 86.35 mmol•min-1g-1Ru, upgrading 42.96% compared with the activity of conventional Ru/AC prepared using aqueous impregnation. The SC CO2 impregnation could result in Ru uniformly dispersed on the outer surface and in the pore of AC, leadingSubscript textto higher dispersion of Ru and enhanced interaction between AC and Ru. Furthermore, the enhanced interaction induces improved reduce temperature. Consequently, the catalytic activity of Ru/AC catalysts is improved significantly.