Thiophene hydrodesulfurization of a novel Mo/TiO₂ catalyst

A novel Mo/TiO₂ catalyst with the MoO₃ loading of 7.2% (mass fraction) used for hydrodesulfurization (HDS) of thiophene was prepared by the impregnation method, in which mesoporous titania whisker (TiO₂) molding material was used as the support and ammonium heptamolybdate [(NH₄)₆Mo₇O₂₄ ·4H₂O] solution as the impregnation solution. The catalyst was well characterized by some techniques, such as X-ray diffraction (XRD), N₂ adsorption-desorption, and its HDS activity for thiophene was evaluated in a continuous-flow fixed-bed micro-reactor under different reaction conditions. Furthermore, the stability of novel Mo/TiO₂ catalyst in HDS reaction of thiophene was also investigated. The results indicated that the novel catalyst was in anatase phase. The specific surface areas of TiO₂ whisker and novel Mo/TiO₂ catalyst were 93 m²/g and 72 m²/g, their pore volumes were 0.27 cm³/g and 0.23 cm³/g, respectively, and there was no obvious reduction in specific surface area and pore volume between them. When the Mo/TiO₂ catalyst was used to catalyze the HDS of thiophene, its activity could reach higher level in 5 h, and the mass fraction of thiophene in model solution could be reduced from 1300 μg/g to 5 μg/g. The thiophene conversion of HDS over the Mo/TiO₂ catalyst could reach near 100% under reaction temperature of 300-330°C, H₂ pressure of 1.5-3.0 MPa, H₂/oil volume ratio of 155-250 and LHSV of 3.0-5.0 h^-1, and no obvious evidence of deactivation for the catalyst could be seen after running for 500 h.