Hydrodesulfurization catalysis by transition metal sulfides

The primary effect in the hydrodesulfurization of dibenzothiophene by transition metal sulfides is “electronic,” i.e., it is related to the position the metal occupies in the periodic table. This effect, which determines the ability of the transition metal sulfides to catalyze the HDS reaction, varies over three orders of magnitude across the periodic table. The first-row transition metal sulfides are relatively inactive, but the second- and third-row transition metals show maximum activity with Ru and Os. HDS activity as a function of periodic position yields typical “volcano” plots.