Synthesis of Polymer–Metal Composites by the Impregnation of Hypercrosslinked Polystyrene with Palladium Compounds in Supercritical Carbon Dioxide and Their Catalytic Activity in the Liquid-Phase Hydrogenation of Diphenylacetylene

Composites—palladium metal particles in a polymer matrix—are obtained by impregnation of hypercrosslinked polystyrene with palladium compounds in supercritical carbon dioxide (SC-CO2) followed by molecular hydrogen reduction. The synthesized composites exhibit a high level of catalytic activity in the liquid-phase hydrogenation of diphenylacetylene (DPA). The turnover frequency (TOF) is 15–50 min–1 and the selectivity in the formation of diphenylethylene is 60–80% at ~90% conversion of the substrate.