Abstract: Molybdenum carbide and nickel-molybdenum carbide catalysts were prepared by temperature-programmed reduction using a CH4/H2 gas mixture to carburize molybdenum trioxide and nickel-molybdenum oxide. X-ray diffraction patterns showed that the crystals were β-Mo2C and Ni-Mo2C, respectively. The effects of nickel promoter on the preparation of molybdenum carbide and its catalytic performance for hydrodesulfurization of dibenzothiophene (DBT) were studied. The results indicated that adding a proper amount of the nickel promoter could decrease the carburizing temperature, increase the BET surface area, and markedly promote the DBT hydrodesulfurization activity of the molybdenum carbide catalysts. When the Ni/Mo atom ratio was 0.3, the synergistic interaction between Ni and Mo was the maximum. The hydrodesulfurization conversion of DBT over the Ni-Mo2C catalyst reached 96.25% under the reaction conditions of 330 ℃, 3.0 MPa, and space velocity 8 h-1, and the conversion was 1.57 times higher than that of Mo2C.

Key words: nickel, molybdenum trioxide, molybdenum carbide, dibenzothiophene, hydrodesulfurization