Novel supported catalyst for hydrodesulfurization reaction

Combination of iridium sulphide catalytic phase and novel magnesium oxo-fluoride supports (MgF2–MgO) allow preparation of new highly active catalysts for the hydrodesulfurization reaction. A series of supports containing MgO in the amount of 10–90 mol% have been prepared by the sol-gel method. Their surface areas and pore size distributions have been investigated by BET and BJH methods, respectively. The catalysts containing 0.5 wt.% iridium have been obtained by impregnation of the supports with a solution of hexachloroiridium acid. Dispersion of iridium and mean size of the crystallites have been determined on the basis of hydrogen chemisorption. The activity of the catalysts in the reaction of hydrodesulfurization of thiophene at 400 °C under atmospheric pressure has been measured. The effect of the MgO content on the texture of MgF2–MgO supports, iridium dispersion and activity of the iridium catalysts in the hydrodesulfurization reaction has been determined. The introduction of MgO into magnesium fluoride in the content of 60–70 mol% has been found to result in even tenfold increase in the surface area accompanied by the maximum of dispersion and catalytic activity.