Platinum-containing polymeric catalysts in direct l-sorbose oxidation†
Impregnation of hypercrosslinked polystyrene (HPS) with tetrahydrofuran (THF) or methanol solutions containing platinic acid resulted in the formation of Pt(II) complexes within the nanocavities of HPS. The highest selectivity (98% at 100% conversion) measured during the catalytic oxidation of L-sorbose in water was obtained with the HPS-Pt-THF complex. The structure of the catalyst isolated after the induction period was analyzed by transmission electron microscopy and X-ray photoelectron spectroscopy. Electron micrographs revealed enlarged Pt nanoclusters, which were most likely responsible for the high catalytic activity and selectivity observed.