Effects of Ni Loading and Presulfidation on Reactivity of Thiophene Hydrodesulfurization over NiW/γ-Al_2O_3 Catalysts

The thiophene hydrodesulfurization (HDS) over NiW/ γ Al 2O 3 catalysts were carried out in a continuous flow reactor. The sulfided NiW/ γ Al 2O 3 catalysts were characterized by X ray photoelectron spectroscopy and micro area element analysis. The catalyst components, sulfidation method, sulfidation degree, and reaction conditions are the factors that influence the HDS reactivity of the NiW/ γ Al 2O 3 catalysts. The optimum Ni/(Ni+W) atomic ratio of the catalyst sulfided at lower temperature (300 ℃) is 0 50 for getting the maximum thiophene HDS reactivity when the reaction temperature is 260～290 ℃, whereas the optimum Ni/(Ni+W) atomic ratio is 0 23 when the reaction temperature is 330～360 ℃. The thiophene HDS reactivity of the catalysts increases with the increase of sulfiding temperature from 300 to 450 ℃. It is shown that the catalyst with a higher sulfidation degree has a higher HDS reactivity.