Application of supported metallic catalysts in catalytic hydrogenation of arenes

Since arenes generally exist in coals and their derivatives, petroleum, crop stalks and even liquid fuels, such as gasoline and diesel, catalytic hydrogenation of arenes is a very important process both for hydroconverting fossil and biomass resources and for deeply upgrading liquid fuels. Supported metal-catalyzed hydrogenation is still the primary method for reducing arenes and heteroatomic species. Both noble and non-noble metals as well as a variety of alloys have been extensively investigated as the active species of catalysts. The catalytic activity for arene hydrogenation and the sulfur-resistance of catalysts are attributed to the nature of both metals and supports. As widely used supports, zeolites can greatly improve the sulfur-resistance and hydrogenation activity of catalysts due to their distinct channel structure and adjustable acid sites. In addition, some new processes of catalyst preparation have been created to modify the dispersion of metal particles, even to prepare supported metal nanoparticles. The thermodynamics and kinetics of arene hydrogenation have been systematically investigated as well. The hydrogenation order of each aromatic ring is judged by the superdelocalizability and the reaction order greatly depends on the nature of catalyst and the reaction conditions.