Hydrodesulfurization of dibenzothiophene over CoMo/HMS and CoMo/Ti-HMS catalysts

Hexagonal mesoporous materials (HMS) with and without titanium were used as supports for preparation of CoMo HDS catalysts. The supports and the catalysts were characterized by adsorption–desorption of nitrogen, XRD, DRS UV–vis, TPR and DRIFTS in the OH region. The catalytic activity of the samples was evaluated in the reaction of hydrodesulfurization of dibenzothiophene. The activity of the CoMo/HMS and CoMo/Ti-HMS catalysts was compared to that of a conventional industrial CoMo/Al2O3 catalyst. The CoMo/Ti-HMS catalyst demonstrated to be more activate than Ti-free catalysts. The presence of Ti ions into the HMS framework impedes the formation of Co2SiO4 and of β-CoMoO4 inactive phases. It is suggested that the higher activity of the Ti-containing catalysts is related to the better dispersion of the supported CoMo phase, the higher concentration of octahedral Co2+ species, larger pore size diameter and lower reduction-sulfidation temperature of the supported species.