Silica Gel-Supported, Metal-Promoted MoS2 Catalysts for HDS Reactions

Silica-supported, metal-promoted MoS2 catalysts were prepared. Sol–gel method was used for providing the SiO2 support as well as for including the catalyst precursors and promoter in one single step of preparation. The general idea in this approach is to obtain the promoted MoS2 catalyst phase finely and uniformly distributed in the SiO2 support. Scanning electron microscopy of the obtained catalysts shows a fine and homogeneous distribution of the metal-promoted MoS2 particles on the SiO2 matrix with surface area between 62 and 104m2/g. Metal promoter affects the surface area, pore size distribution and the hydrodesulfurization (HDS) activity and selectivity. When different promoters were used at the same amount, the highest selectivity for direct C–S bound cleavage is observed for Ru/MoS2/SiO2 catalyst, and at different amounts of Co the highest selectivity was occurred with Co/MoS2/SiO2 at 12% of Co/MoS2, X-ray diffraction studies showed that the catalysts are poorly crystallized with a very weak intensity of the (002) line of 2H-MoS2. Comparison on the catalytic activities of the catalysts with different metal promoters was made. Catalytic activity results showed the method of preparation used in this study is successful in producing very efficient catalysts for the HDS of dibenzothiophene (DBT). Silica-supported, cobalt-promoted MoS2 catalyst showed the highest activity.