Collect. Czech. Chem. Commun. 1985, 50, 300-305

Effect of partial removal of nickel or cobalt promotors from molybdenum sulphide hydrorefining catalysts on their activity

Jan Uchytil, Petr Novosad, Jiří Sedláček and Miloš Kraus

Institute of Chemical Process Fundamentals, Czechoslovak Academy of Sciences, 165 02 Prague 6-Suchdol


Three commercial nickel-molybdenum and cobalt-molybdenum hydrorefining catalysts were sulphided and then treated with 10% hydrochloric acid. The amount of extracted nickel or cobalt increased with time of leaching; the activity of the catalysts for hydrogenation of toluene was enhanced by short leaching but was decreased when the acid treatment was prolonged. X-ray photoelectron spectroscopy of the Ni-Mo catalyst showed that the leaching results in major changes in the surface concentrations of nickel and molybdenum.