Oxidative desulfurization of a model liquid fuel over an rGO-supported transition metal modified WO3 catalyst: Experimental and theoretical studies

Abstract

The XW/rGO compounds (XW = Co or Ni modified WO3) have has been utilized as catalysts in the oxidative desulfurization (ODS) process of a liquid model fuel containing dibenzothiophene (DBT). Various characterization methods were carried out to complete evaluations of the prepared catalysts. Moreover, using the GC–MS method, it became clear that the final product of the process was dibenzothiophene sulfone (DBTO2). Furthermore, results showed that under the optimized conditions (oxidant to substrate molar ratio = 6, 75 °C and catalyst to substrate molar ratio = 0.08), the DBT content of a model fuel was declined by 100% only within a reaction duration time of 45 min using the CoW (20)/rGO catalyst. Also, the results obtained from the DFT study revealed that, for an efficient reaction over the surface of the catalyst, along with the S⋯O chalcogen interaction, the strength of the H-bonds interactions (H⋯O) between the DBT and active sites on catalysts may have tuned-up the driving force of the reaction. Ultimately, the results indicated that the charge transfer at the XW/rGO interface may be tuned by selecting impurity used alongside the WO3 species.