Clear oxidation of cyclohexanone to adipic acid catalyzed by H_6P_2W_9Mo_9O_(62)·24H_2O

Tungstomolybdophosphate acid with Dawson structure was prepared by hydrothermal synthesis and characted by means of FT-IR,TG-DTA.The synthesis of adipic acid with cyclohexanone and 30 percent hydrogen peroxide was carried out as a probe reaction to study the catalytic activity.The main effects of the reaction were optimized with orthogonal experiments,the mechanism was proposed.The results showed that under the optimal condition,i.e.the mole ratio of C6H10O∶H2O2∶H2C2O4∶ H6P2W9Mo9O62.24H2O=100∶400∶1.00∶0.15,the reaction temperature was 100℃,irradiation time 5h,the isolated yield of adipic acid could reach 71.6% and its purity was 99.7%.The filtration containing the catalyst could be concentrated by the rotary evaporation and be reused five times by easily separation of the product after reaction,the isolated yield of adipic acid was still above 50.3%.