Immobilization of phosphotungstic acid on amine-grafted graphene oxide via a facile and efficient solid-phase reaction for the selective oxidation of cyclohexanol

Phosphotungstic acid was immobilized on the surface of 3-aminopropyltrimethoxysilane -grafted graphene oxide by one-step solid phase reaction between acid and base. The synthesized catalyst was characterized by Fourier transform infra-ed spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy, thermogravimetry, elemental analysis, NMR and contact angle measurements. The catalyst was exploited for selective oxidation of cyclohexanol to cyclohexanone. The catalytic results indicated that the cyclohexanol conversion of 89.2% along with cyclohexanone selectivity of 95.4% was achieved in selective oxidation of cyclohexanol using H2O2 as oxidant over the as-prepared catalyst. It also could be easily recovered and reused for at least four times without any significant loss in activity.