Performance evaluation of the carbon nanotubes supported Cs 2.5H 0.5PW 12O 40 as efficient and recoverable catalyst for the oxidative removal of dibenzothiophene

Abstract

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 Cs 2.5H 0.5PW 12O 40, a new multi-walled carbon nanotube (MWNT) supported catalyst (Cs 2.5H 0.5PW 12O 40/MWNT) has been developed in this study. Through experimental evaluations, Cs 2.5H 0.5PW 12O 40/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 H 2O 2 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 H 2O 2 in the presence of Cs 2.5H 0.5PW 12O 40/MWNT after 160 min. Moreover, the new catalyst developed is recoverable. The recovered Cs 2.5H 0.5PW 12O 40/MWNT demonstrates quite close catalytic activity to that of the fresh. As a whole, Cs 2.5H 0.5PW 12O 40/MWNT has a high potential for using as an effective catalyst for deep desulfurization of diesel.