SBA-15 as Support for Ni-MoS2 HDS Catalysts Derived from Sulfur-containing Molybdenum and Nickel Complexes in the Reaction of HDS of DBT: An All Sulfide Route

MoS2 HDS catalysts promoted with Ni supported on SBA-15 were synthesized from sulfur containing Mo (ammonium thiomolybdate, ATM, and tetramethylammonium thiomolybdate, TMATM) and a Ni complex (Nickel diethylthiocarbamate, NiDETC). The catalysts have been characterized by X-ray diffraction (XRD), N-2-physisorption and High-resolution transmission electron microscopy (HRTEM). The catalytic performance in the hydrodesulfurization (HDS) reaction of dibenzothiophene (DBT) was examined at T = 623 K and P-H2 = 3.4 Mpa. In comparison with the impregnation mode, the nature of the employed thiomolybdate complex shows a stronger influence on the MoS2 morphology and consequently on the HDS activity of DBT. A similar high HDS activity to a commercial NiMo/gamma-Al2O3 catalyst despite the pronounced stacking number is shown for a Ni MoS2/SBA-15 catalyst derived from ATM. The catalysts derived from TMATM showed lower HDS activities compared to the catalysts obtained from ATM precursors due to probably the presence of closed shell structures (nano-onions) of MoS2 which offer significantly smaller amount of HDS active sites (edge sites). Moreover, the HYD/DDS ratios are interestingly higher with respect to the HYD/DDS ratio of the commercial NiMo/gamma-Al2O3 catalyst which could be ascribed to the generation of multilayered MoS2 active phase.