Preparation of WO3/CNT catalysts in presence of ionic liquid [C16mim]Cl and catalytic efficiency in oxidative desulfurization

Abstract

AbstractBACKGROUNDWith the strict regulation for environmental protection, the removal of sulfur compounds from fuels is becoming more and more urgent. Hydrodesulfurization is one of the most widely used technologies in chemical industry, but its application is limited because of the harsh reaction conditions and the low efficiency in removal of aromatic organic sulfide. In this work, catalysts consisting of tungsten trioxide immobilized on carbon nanotubes (WO3/CNT) in the presence of ionic liquid [C16mim]Cl were prepared for the oxidative desulfurization of aromatic organic sulfide.RESULTSThe catalysts were systematically characterized by TG‐DSC, XRD, UV–visible, FTIR, Raman, SEM, TEM, XPS and BET. The dispersion of CNT and the crystal phase of WO3 on the carrier (CNT) were changed in the presence of ionic liquid [C16mim]Cl. The WO3 exists in tetrahedral form when the mass ratio of [C16mim]Cl to CNT is 2. The WO3/CNT catalyst demonstrates better activity in the oxidative desulfurization system, with the removal of dibenzothiophene (DBT) reaching 90.73% under optimal conditions. The oxidation process of DBT follows pseudo‐first‐order kinetics, and the activation energy is about 29.69 kJ mol−1. Dibenzothiophene sulfone (DBTO2) was determined to be the oxidative product of DBT.CONCLUSIONThe results illustrated that the oxidative desulfurization efficiency of different forms of WO3 loaded on the same carrier (CNT) followed the order tetrahedral WO3 > tetragonal phase WO3 > monoclinic phase WO3. © 2019 Society of Chemical Industry