Fe-Co/sulfonated polystyrene as an efficient and selective catalyst in heterogeneous Baeyer-Villiger oxidation reaction of cyclic ketones

A highly efficient catalyst Fe-Co/sulfonated polystyrene (Fe-Co/SPS) was introduced and synthesized, which catalyzed BV oxidation of ketones with aqueous hydrogen peroxide to give the corresponding lactones in high yield and selectivity. Solid acid catalyst of Fe-Co/SPS has been prepared by using the 98-wt% sulfuric acid as the sulfonating agent and CoCl2 combined FeCl3 as sources of metal ions. Various physical-chemical characterizations including FT-IR, XRD, SEM and TGA, revealed that bimetallic ions Fe3+-Co2+ species in the sulfonated polystyrene framework were responsible for the catalytic activities. The BV reaction catalyzed by Fe-Co/SPS highlighted the special effects between metal ions and protonic acids as well as solvent-free heterogeneous catalytic oxidation with excellent conversion.