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Abstract

Magnesia-supported Ni-Mo sulfide catalysts were prepared by several versions of aqueous impregnation method and by the unconventional method of precipitation-adsorption of sulfides in emulsion water-toluene. The activity of catalysts was tested in hydrodesulfurization of thiophene at pressure of 1.6 Mpa. The samples of Ni-Mo/MgO prepared by impregnation exhibited only 15 – 30% of the activity of Ni-Mo/Al₂O₃ catalysts Shell 324; the principle obstacle was found to be chemical and hydrothermal instability of MgO with high surface area. The activity of samples prepared by precipitation-adsorption was not much lower than that of the impregnated catalysts; this was taken as an indirect evidence of the acid-base interaction between sulfides and MgO surface. It was concluded that the course of low activity of Ni-Mo/MgO catalysts was textural and not chemical; surface area of Ni-Mo active phase in MgO-supported catalysts was supposed to be lower than in Al₂O₃-supported catalysts.