Evaluation of functionalized reduced graphene oxide upgraded with gold nanoparticles as a hybrid nanocatalyst for the solvent-free oxidation of cyclohexene by molecular oxygen

Abstract

In the present study, the allylic oxidation of cyclohexene is investigated using molecular oxygen as an oxidant under environment-friendly conditions in the presence of rGO-dithiooxamide/Au hybrid nanocatalyst (rGO $=$ reduced graphene oxide). This hybrid catalyst comprises nanometric spherical gold particles supported on dithiooxamide-functionalized rGO. The structure of the prepared hybrid catalyst was characterized using FT-IR, XRD, SEM and TEM techniques. The catalytic activity results were found to be dependent on pressure, the amount of hybrid nanocatalyst, reaction time, and temperature. In addition, an 85% conversion and 85% selectivity to 2-cyclohexene-1-one were obtained under optimized reaction conditions. The catalytic activity over a recycled catalyst (rGO-dithiooxamide/Au) remained at a satisfactory state after at least five cycles.

Keywords

• Aerobic oxidation
• Hybrid catalyst
• Cyclohexene
• rGO-dithiooxamide/Au