Performance evaluation of the carbon nanotubes supported Cs2.5H0.5PW12O40 as efficient and recoverable catalyst for the oxidative removal of dibenzothiophene

With the issues of increasingly stringent legislations on sulfur level in transportation fuels, clean fuels research including desulfurization has become a more important subject of environmental catalysis studies. Oxidative desulfurization (ODS) combined with extraction is one of the most promising desulfurization processes. With the loading of Cs2.5H0.5PW12O40, a new multi-walled carbon nanotube (MWNT) supported catalyst (Cs2.5H0.5PW12O40/MWNT) has been developed in this study. Through experimental evaluations, Cs2.5H0.5PW12O40/MWNT was found to be very effective for the oxidative removal of DBT, with a desulfurization efficiency of up to 100%. Factors affecting the process, including reaction temperature, O/S molar ratio, initial sulfur content, catalyst dosage, and pre-immersion time of the catalyst in H2O2 solution, were evaluated, and the favourable operating conditions were determined. Sulfone species was confirmed by GC–MS analysis to be the only product from DBT oxidation by H2O2 in the presence of Cs2.5H0.5PW12O40/MWNT after 160 min. Moreover, the new catalyst developed is recoverable. The recovered Cs2.5H0.5PW12O40/MWNT demonstrates quite close catalytic activity to that of the fresh. As a whole, Cs2.5H0.5PW12O40/MWNT has a high potential for using as an effective catalyst for deep desulfurization of diesel.