Optimization of Supports in Bifunctional Supported Pt Catalysts for Polystyrene Hydrocracking to Liquid Fuels

A series of bifunctional platinum catalysts were prepared, supported on alumina or different zeolites, some of which were submitted to either desilication or dealumination in order to modify their acidic properties. The catalysts were characterized for their structural and textural properties, their acidic properties, including distribution of acid strength and Brønsted and Lewis acidity, their metallic properties, and used in the hydrocracking of polystyrene under kinetic control, where activity in end-of-chain scission and random scission of the polymer has been quantified as well as the distribution of products. Activation energies and pre-exponential factors have been calculated from the kinetic data, and analyzed in terms of compensation effect, in order to extract conclusions on activity, active centers and reaction pathways. Finally, activation energies, both of end-of-chain and random scissions, yield to gasoline fraction and percentage of aromatics in the gasoline fraction have been correlated with catalytic properties in order to extract conclusions on the major catalytic properties affecting catalytic performance in this process, from the point of view of catalytic design.