Preparation of supported phosphotungstic acid catalyst with multi-carriers and using it to green synthesis of adipic acid

Supported phosphotungstic acid catalyst with multi-carriers was prepared. Preparing conditions of the catalyst were:mass ratio of LaCl3 to SnCl4·5H2O to kaolin 1:9:20,impregnation time 12h in alcohol solution of phosphotungstic acid and calcination at 300℃ for 3h. The catalyst was characterized by IR and XRD. And it was used to catalyze the synthesis of adipic acid from cyclohexanone oxidized by 30% hydrogen peroxide without any organic solvent or phase transfer agents. It was helpful to cost reduction,to simplify separation process,to reduce pollution and to increase product quality. Optimal reaction conditions were cyclohexanone 100mmol,catalyst dosage 1.5g,30% H2O2 45mL,the yield of adipic acid could reach 63.9% when refluxing 6h.