Collect. Czech. Chem. Commun. 1991, 56, 580-589

Comparison of MgO-supported Ni-Mo hydrodesulfurization catalysts prepared by impregnation and by precipitation-adsorption in emulsion

Vladimír Koloušek, Pavel Pálka, Eva Hillerová and Miroslav Zdražil

Institute of Chemical Process Fundamentals, Czechoslovak Academy of Sciences,165 02 Prague-Suchdol


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.