Study of sulfur transfer reaction on Ni-Mo/Al₂O₃ catalyst

The bimetal Ni-Mo catalysts supported on γ-Al₂O₃ were prepared and used for the selective hydrogenation of FCC gasoline for sulfur transfer. The reaction mechanism of sulfur transfer on Ni-Mo/Al₂O₃ catalyst was studied and the influence of reaction conditions on sulfur transfer was investigated. The results showed that the reaction of thiol and olefin happened on the active sites of hydrogenation on catalyst surface. Hydrodesulfurization of small molecule thiol firstly produced adsorbed hydrogen sulfide, then the adsorbed hydrogen sulfide reacted with adsorbed olefin and formed macromolecular thiol or thioether; Besides, small molecule thiol can also directly reacted with olefins to produce thioether. The activity of sulfur transfer reaction of Ni-Mo/Al₂O₃ catalyst was improved through the increase of reaction temperature, pressure, and H₂/oil ratio or the decrease of LHSV. The conversion of light sulfur compounds was obviously improved, and mono-olefins selectivity was maintained at around 98%.