Vanadium Oxide-Based Composite Catalysts for the Oxidation of Styrene: A Comparative Study

Vanadium oxide-based composite catalysts were prepared, and their activities in a styrene oxidation reaction were tested. These catalysts included (i) vanadium oxide (VxOy) supported on multi-walled carbon nanotubes (CNTs) (CNTs-VxOy), (ii) a carbon nanotube CNTs-VxOy template coated with γ-Al2O3 (CNTs-VxOy/Al2O3), (iii) γ-Al2O3/VxOy nanoparticles and (iv) vanadium oxide nanotubes (VxOy-NTs). The structure of these catalysts was determined by TEM, SEM, nitrogen adsorption (BET surface area), TGA and FTIR. The oxidation process was examined between styrene and anhydrous hydrogen peroxide which was catalyzed using the above VxOy-based composite catalyst. The vanadium particles embedded on the wall of CNTs have a satisfactory catalytic activity for oxidation. The effect of the operating parameters, including the reaction temperature, solvent type, reaction time, oxidant concentration and catalyst loading, on styrene conversion and benzaldehyde selectivity was studied.