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. [ABSTRACT FROM AUTHOR]