Preparation of WO_3/SiO_2 catalyst for green oxidation of cyclohexanone to adipic acid with H_2O_2

Adipic acid was synthesized by WO3/SiO2-catalyzed oxidation of cyclohexanone with 30%hydrogen peroxide in the absence of phase-transfer catalyst.The effect of several reaction parameters which were the amount of catalyst and hydrogen peroxide,reaction time,acidic ligand,reusability and so on was investigated on the oxidation process.Results showed that when the cyclohexanone 0.1 mol,catalyst amount 0.9 g,30% H2O2 50 mL,refluxing 5 h,the yield of adipic acid could reach 67.2% without acidic ligand.In addition,the catalyst had certain repeated applicability.