Characterization and HDS activity of sulfided CoMoW/SBA-16 catalysts: Effects of P addition and Mo/(Mo + W) ratio. (15th June 2017)

• Record Type: Journal Article
• Authors: Huirache-Acuña, R.; Pawelec, B.; Rivera-Muñoz, E.M.; Guil-López, R.; Fierro, J.L.G.
• Is Part Of: Fuel. Volume 198(2017)
• Page Start: 145
• Page End: 158
• Publication Date: 2017-06-15
• Subjects: HDS -- Dibenzothiophene -- SBA-16 -- Phosphorus -- CoMoW catalysts; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2016.09.042
• Languages: English
• ISSNs: 0016-2361

Abstract

Graphical abstract: CoMoW catalyst prepared with Mo/(Mo + W) atomic ratio of 0.4 and supported on SBA-16 modified with P was the most active. Highlights: HDS activity of CoMoW/SBA-16 sulfide catalysts depends strongly on the Mo/(Mo + W) atomic ratio. CoMoW catalyst prepared with Mo/(Mo + W) atomic ratio of 0.4 and supported on SBA-16 modified with P was the most active. The most active catalyst exhibited the highest surface exposure and sulfidation degree of W species. Abstract: Two series of SBA-16-supported CoMoW ternary sulfide catalysts with atomic ratio r = Mo/(Mo + W) ranging from 0.3 to 0.7 were prepared by the simultaneous impregnation of SBA-16 and phosphated-SBA-16 substrates with metal precursors. The samples were characterized by a variety of techniques (chemical analysis, N2 physisorption, SEM, XRD, DRS UV–vis, TPR, TPD-NH3, Raman spectroscopy, HRTEM, XPS and coke burning) . The catalytic performance was evaluated in the hydrodesulphurization (HDS) of dibenzothiophene (DBT), carried out in a batch reactor at 350 °C and 3.1 MPa of total H2 pressure. The maximum activity at the same atomic ratio r = 0.4 was observed for the catalysts supported on SBA-16 modified with phosphorous ( r = 0.4(P)). HRTEM evidenced that this was because different MoS2 crystalline structures were formed: the P-free sample prepared with Mo/(Mo + W) atomic ratio of 0.6 ( r = 0.6) exhibited the MoS2 -2H crystalline structure whereas the P-containing samples prepared with Mo/(Mo + W) atomic ratio of 0.4 ( r = 0.4(P)) exhibited the interplanar distance corresponding to (0 0 3) planes of MoS2 -3R crystalline structure. Additionally, the best activity of the r = 0.4(P) sulfide catalyst was linked with the enhancement of the WS2 species surface exposure accompanied with a larger sulfidation degree of W species (from XPS).