Catalytic Performance of Carbon Nanotubes Supported 12-Tungstosilicic Acid in the Electrooxidation of Cyclohexane to Cyclohexanone and Cyclohexanol

摘要

Carbon nanotubes-supported 12-tungsto-silicic materials (referred as CNT- SiW12-x, where x is the loading of H4SiW12O40, abbreviated as SiW12 were prepared and characterized by means of FTIR, XRD, and polarography. The prepared catalysts and attached onto glassy carbon (GC) electrodes by using polyvinylidene difluoride (PVDF) as binder. The resulting carbon supported SiW12 modified electrodes were investigated by cyclic voltammetry (CV) and tested for the electrooxidation of cyclohexane to cyclohexanone (K) and cyclohexanol (A). It has been found that the cyclohexanone, cyclohexanol and cyclohexyl hydroperoxide (CyOOH) are formed as major products of the reaction. Exchanged electronic charge and reaction time had an obvious influence on the catalytic performance of the catalyst. Short reaction time and low exchanged electronic charge favor the formation of cyclohexanol. High exchanged electronic charge and long reaction time favor the electrooxidation of cyclohexanol to cyclohexanone. The optimum condition for the formation of the cyclohexanone, which is needed for the production of the ε-caprolactam, is high exchanged electronic charges.