An unexpected pathway for hydrodesulfurization of gazole over a CoMoS active phase supported on a mesoporous TiO₂ catalyst

Abstract

Using dual mesoporous titania as a support, due to the presence of intrinsic Brönsted acid sites, the main approach to 4,6-dimethylbenzothiophene (46DMDBT) hydrodesulfurization (HDS) becomes the direct desulfurization (DDS) route through isomerization and dismutation reactions, instead of the hydrogenation (HYD) pathway usually observed with a conventional promoted (by Ni or Co) MoS/AlO catalyst.

Deep hydrodesulfurization of 4,6-dimethydibenzothiophene over CoMoS/TiO2 catalysts: Impact of the TiO2 treatment

“…). As reported previously [18,19], mesostructured TiO 2 induced the presence of Brønsted acidity which decreased with the temperature of the treatment of TiO 2 mainly at 550°C and 650°C. In the same way a high decrease of the total activity (A T ), HDS activity (A HDS ) and of Acid activity (A Acid. )…”

“…Mesostructured titania have been synthesized according to the procedure reported in previous work using the triblock copolymer P123 (EO) 20 (PO) 70 (EO) 20 (labeled as P123) as surfactant [18][19]. To investigate the effect of thermal treatment temperature on the support properties and thus on the catalyst performance, the final mesostructured TiO 2 support (after Soxhlet extraction using ethanol) is treated at different temperatures from 380°C to 650°C for 1h under synthetic air atmosphere.…”

“…As reported in previous papers [18,19], the catalysts are sulfided in situ in a fixed flow reactor using a sulfiding feed made of 5 % wt of dimethyl disulfide (DMDS) in n-heptane as solvent at a temperature of 350°C under a 4.0 MPa of total pressure during 14 hours. The temperature was then lowered to the reaction temperature (340°C).…”

“…Other supports like silica, zeolites, carbon, titania, and mixed metal oxides are reported to provide significant improvements compared to γ-Al 2 O 3 [12][13][14][15][16][17]. Among all these supports, TiO 2 is particularly intriguing [18][19][20][21]. For example, Klimova et al [20] have shown that NiMo catalysts supported on titania nanotubes allowed reaching high conversions of 4,6-DMDBT with a much lower proportion of hydrogenated product than using NiMo/Al 2 O 3 catalyst.…”

XPS and Raman study of the active-sites on molybdenum disulfide nanopetals for photocatalytic removal of rhodamine B and doxycycline hydrochlride

“…MoS 2 with S-Mo-S sandwich layer structure 1 has some applications including catalytic hydrodesulfurization of petroleum, 2,3 wear resistance, 4,5 energy storage 6,7 and photocatalysis application. 8,9 For all the above applications, the number of the active-sites plays a crucial role.…”