Highly dispersed CoMoS phase on titania nanotubes as efficient HDS catalysts

Influence of Na content on behavior of NiMo catalysts supported on titania nanotubes in hydrodesulfurization

“…Thus, CoMo catalysts supported on high-surface-area (more than 300 m 2 g À1 ) nanostructured titania powder showed an activity twice as high in dibenzothiophene HDS as a commercial CoMo/alumina catalyst [15]. Similar results were obtained for CoMoS catalysts supported on titania nanotubes with an internal diameter of $5.5 nm and a surface area of 236 m 2 g À1 [16,17]. High HDS activity observed in these works was attributed to high dispersion of catalytically active MoS 2 particles and high sulfidability of Mo species [15][16][17].…”

HDS performance of NiMo catalysts supported on nanostructured materials containing titania

“…CoMo catalysts supported on titania nanotubes also showed high activity in HDS of dibenzotiophene [18,19] and selective hydrodesulfurization of thiophene [20]. High HDS activity observed in the above works was attributed to high dispersion of catalytically active MoS 2 particles and high sulfidability of Mo species [17][18][19]. Regarding NiW catalysts, it was also found that the catalysts supported on TiO 2 nanotubes resulted in two times higher thiophene conversion in comparison with the alumina and titania supported ones [21].…”

“…For example, CoMo catalysts supported on high surface area (more than 300 m 2 /g) nano-structured titania powder showed activity twice higher in dibenzothiophene HDS than a commercial CoMo/alumina catalyst [17]. CoMo catalysts supported on titania nanotubes also showed high activity in HDS of dibenzotiophene [18,19] and selective hydrodesulfurization of thiophene [20]. High HDS activity observed in the above works was attributed to high dispersion of catalytically active MoS 2 particles and high sulfidability of Mo species [17][18][19].…”

Slurry Impregnation of ZrO2 Extrudates: Controlled EggShell Distribution of MoO3, Hydrodesulfurization Activity, Promotion by Co

“…The promotional effect of 8.5 was reached after deposition of Co onto presulfided Mo catalysts supported on ZrO 2 -TiO 2 with molar ratio ZrO 2 /TiO 2 60/40 and BET surface area 165 m 2 g -1 , which resulted in 10% activity improvement in comparison with Al 2 O 3 supported catalyst [44]. Two fold higher HDS activities of CoMo catalysts were reported over nano-structured TiO 2 possessing BET surface area about 330 m 2 g -1 [46] and TiO 2 nanotubes of BET surface area 236 m 2 g -1 [47] than over Al 2 O 3 -supported counterparts but without referring on promotional effects. A relatively high promotional effect of 10 was obtained in the case of Ni supported over wide-pore ZrO 2 -TiO 2 Mo catalyst (molar ratio ZrO 2 /TiO 2 30/70 and BET surface area about 300 m 2 g -1 ) employing chelating agent assisted impregnation technique [45].…”

“…Open symbols-Mo catalysts, filled symbols-CoMo catalysts with Co deposited by SIM or CIM, halffilled symbols-CoMo catalysts with Co deposited by MIM over presulfided Mo catalysts promotional effects of 2.4 and 2.9 in the case of Co over zirconia-and titania-supported catalysts, respectively, in [42] or 3.3 over both supports in [16] were reported while they were about 5 or 11 over alumina-supported counterparts resulting in high integral HDS activity. On contrary, it is believed that further improvement of the ZrO 2 and TiO 2 based catalysts lie in tailored preparation of their mixed form with desirable textural properties [43][44][45] or nanostructured forms [46,47]. The CoMo catalyst supported on solvo-thermally treated ZrO 2 -TiO 2 with molar ratio ZrO 2 /TiO 2 30/70 and BET surface area 313 m 2 g -1 exhibited promotional effect about 3.2 but exceeded the HDS activity of a reference Al 2 O 3 -supported counterpart about twofold [43].…”