Effect of phosphorus addition on unsupported Ni–Mo–W sulfide catalysts prepared by the in situ activation of nickel/tetramethylammonium thiomolybdotungstate Original Research Article

The effect of phosphorus addition was studied during the synthesis of unsupported trimetallic Ni–Mo–W catalysts prepared by the in situ activation of nickel-containing tetramethylammonium thiomolybdotungstate during the hydrodesulphurization (HDS) of dibenzothiophene (DBT). The trimetallic Ni–Mo–W precursors were prepared by the reaction of tetramethylammonium thiomolybdotungstates salts, [(CH3)4N]4MoWS8, with NiCl2 and H3PO4 at P/Mo molar ratio of 0, 0.1, 0.5 and 1.0. These precursors are named Ni/[(CH3)4N]4MoWS8, P0.1/Ni/[(CH3)4N]4MoWS8, P0.5/Ni/[(CH3)4N]4MoWS8 and P/Ni/[(CH3)4N]4MoWS8, to give C1, C1P0.1, C1P0.5 and C1P catalysts, respectively. Catalysts were characterized by nitrogen adsorption studies, TEM, EDX, SEM and XRD.