Understanding of Hydrotreating on Unsupported Ni-Mo, Ni-W and Ni-Mo-W Sulfides

Unsupported sulfide W-Mo-Ni catalysts are well-characterized and tested in simultaneous hydrodenitrogenation and hydodesulfurization reactions of model compounds. The presence of tungsten accelerates the hydrogenation rates, whereas nickel enhances the intrinsic activity. Coordinative unsaturated sites, Ni-promoted sites and the synergy between them lead to high catalytic activity.