Active Phase of Sulfide-Type Catalyst and Its Activity for Hydrodesulfurization

Sulfide-type catalysts were prepared by isochoric impregnation and characterized by means of XPS,TEM and high pressure DSC.The impregnation solutions were prepared by adding the organic additives into sulfide precursor solutions,which was synthesized from metallic salts and sulfurizing agents.The hydrodesulfurization activity and active phase formation of the catalysts were studied.Metals in the sulfide-type catalysts first changed into transitive +5 valence state,and then gradually changed into MoS2 phase.The organic additives can not only change the sulfuration process,promote the dispersion of nickel metal on the MoS2 surface and formation of highly active Ni-Mo-S phase,but also decrease the exothermic peak to avoid too high temperature in the process.The active metals on the sulfide-type catalyst surface were sulfurized completely and the hydrodesulfurization activity of the sulfide-type catalysts was high.