The catalytic activities of several alumina-supported monometallic sulfides covering a wide range of heats of formation or metal-sulfur bond energies, namely, Mn, Fe, Zn, Cu, Ni, Ru, Mo, and Re sulfides, have been measured for the hydrogenation of cyclohexene, the hydrodesulfurization (HDS) of benzothiophene, and the hydrodesulfurization of dibenzothiophene under typical hydrotreating conditions. For the hydrodesulfurization of dibenzothiophene a volcano curve similar to the one reported for bulk sulfides (Pecoraro, T., and Chianelli, R. R., J. Catal. 67, 430 (1981)) is found when the HDS activities are plotted versus the metal-sulfur bond energy, suggesting that the alumina support has no major influence on the volcano curve. For cyclohexene hydrogenation and benzothiophene HDS different trends are found, suggesting that the activity trends depend on the nature of the reactant and/or reaction. The activities expressed in moles of reactant per mole of sulfided metal of Mn, Fe, Zn, Cu, and Ni sulfides are found to be very low, whereas the activities of Ru, Mo, and Re sulfides are high and of the same Order of magnitude. (C) 2000 academic Press.