Effect of the carbon support nano-structures on the performance of Ru catalysts in the hydrogenation of paracetamol

摘要

Ru catalysts supported on three types of graphite nanofiber materials, stacked-cup (PR24-HHT), platelet (CNF-P) and bamboo-like (CNF-B), have been synthesized and characterized by HRTEM and calorimetry of CO adsorption. The influence of the support nanostructure on their catalytic performance in the selective hydrogenation of paracetamol was also studied. An inverse correlation between the heats of CO adsorption and the activity and stereoselectivity to the trans-4-acetamidocyclohexanol was found. The results have been rationalized in terms of the morphology and electronic properties of the metal particles. These features are controlled by the different location of the crystallites and the metal-support interactions induced that eventually depend on the nanostructure of the support. As a consequence the supports seem to modify the Ru nanoparticles surface structures, and the shift in selectivities can be related with variations of the reactant chemisorption over such Ru surfaces.