Catalytic activity of MoS2 nanotubes in the hydrodesulphurization reaction of dibenzothiophene

In the need for developing better fuels and as a consequence better hydrodesulphurization catalysts (HDS), new generations of catalysts are necessary to reduce substantially the sulfur content in diesel and gasoline fuels. HDS are catalytic processes that involve Mo or W-based catalysts, often doped with other transition metals. We synthesized MoS2 nanotubes by reacting MoO3 with thiourea and used them as catalysts for the hydrodesulfurization of dibenzothiophene in a batch reactor. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy techniques were used to characterize their morphology and structure. The results indicated the hexagonal crystalline structure or MoS2 and large yields of the MoS2 nanotubes with unusual square or rhomboid faceted shapes. The catalytic behavior of the MoS2 nanotube catalysts showed that the direct desulfurization pathway prevailed over the hydrogenation (HYD) pathway. This finding was attributed to the low rim/edge sites ratio, induced by the size and morphology of the nanotubes showing large flat area which is responsible for the biphenyl (BP) selectivity.