Oxidation of alcohols to carbonyl compounds with H2O2 in water catalyzed by polyoxometalate-based hyper-crosslinked ionic polymer

The oxidation reaction involving hydrogen peroxide (H₂O₂) in water is of great attraction in fundamental research and industrial application, but there is still a long way to go. Herein, a new hybrid catalyst PW@Py-HIP was successfully synthesized by immobilization of phosphotungstic anions onto/into the pyridinium-based hyper-crosslinked ionic polymer using a post-synthetic strategy. This facile synthetic method afforded heterogeneous catalyst with a large specific surface area of 428.7 m²·g⁻¹ and stable polymeric skeleton. The amphiphilic PW@Py-HIP exhibited remarkable catalytic activity and quantitative selectivity for the oxidation of alcohols into carbonyl compounds with H₂O₂ in water. The turnover frequency (TOF) and turnover number (TON) values reached 1088.9 h⁻¹ and 4083.3, respectively. Owing to its good heterogeneous nature, PW@Py-HIP can be recycled for six times without significant loss of activity. The developed catalytic system confirmed to be beneficial toward the synthesis of related carbonyl compounds from various alcohols with appreciable conversions.