New HDS catalysts based on thiol functionalized mesoporous silica supports
Mesoporous silicas, SBA-15 and HMS, were functionalized with mercaptopropyl groups by the single step procedure. The organomodified silicas and the bare mesoporous silicas were used as supports for CoMo catalysts. The final materials were analysed by several techniques such as N2 physisorption (BET), DRS UV–vis, XRD, SAXS, TPR and XPS. The catalytic activities were evaluated in the hydrodesulfurization reaction of thiophene. The effect of the two different silica textures on the catalyst activity was rather small. However a significant enhancement of the catalytic activity was observed for the catalysts supported on the functionalized silicas. Taking into account the structural and spectroscopic results, the superiority of the thiol containing catalysts is attributed to the improved dispersion and reducibility of the precursor oxide species.
Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (143 K)Download as PowerPoint slideResearch highlights▶ Mercaptopropyl functionalization of mesoporous silicas produces more active CoMo catalysts with respect to unfuctionalized supports. ▶ The incorporation of the thiol groups enhanced significantly the reducibility of the catalysts. ▶ β-CoMoO4 phase present in all samples, is highly dispersed over the functionalized catalysts. ▶ A relationship between the precursor β-CoMoO4 phase and the catalyst activity is observed.
Journal: Applied Catalysis A: General - Volume 386, Issues 1–2, 30 September 2010, Pages 43–50