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

摘要

MoS2 HDS catalysts promoted with Ni supported on SBA-15 were synthesized from sulfur containing Mo(ammonium thiomolybdate,ATM,and tetramethyl-ammonium thiomolybdate,TMATM)and a Ni complex(Nickel diethylfhiocarbamate,NiDETC).The catalysts have been characterized by X-ray diffraction(XRD),N2-physisorption and High-resolution transmission electron microscopy(HRTEM).The catalytic performance in the hydrodesulfurization(HDS)reaction of dibenzotbio-phene(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.