Effect of Supports on the Catalytic Hydrogenation of Polystyrene

The heterogeneous catalytic hydrogenation of polystyrene dissolved in cyclohexane over Pd-containing catalysts have been investigated in a batch reactor. Ultraviolet technique was employed to monitor the hydrogenation extent. The catalyst properties were modified by sol-gel methods. The effects of temperature and catalyst support were investigated over the ranges 500-1,500 psig and 138 to 190 A degrees C. In each case, fully saturated materials were obtained with no chain scission (i.e., degradation). The rate of hydrogenation showed strong dependence on the catalyst support.