Sulfur elimination by oxidative desulfurization with titanium-modified SBA-16

• Published in: Catalysis today 2016-08, Vol.271, p.102-113
• Main Authors: Rivoira, Lorena P., Vallés, Verónica A., Ledesma, Brenda C., Ponte, María V., Martínez, María L., Anunziata, Oscar A., Beltramone, Andrea R.
• Format: Article
• Language: English
• Subjects: ODS; Reaction kinetics; Ti incorporation method; Ti-containing SBA-16; TiO2
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2015.07.055

•Ti-SBA-16 and TiO2/SBA-16 were synthesized with high load of Ti.•TiO2/SBA-16 showed high activity in DBT oxidation at mild conditions.•Mass transfer limitation was found in three phases system.•Kinetic constants and apparent activation energy of S-compounds were determined. TiO2-modified mesoporous SBA-16 and titanium-substituted mesoporous SBA-16 were developed and tested in the oxidative desulfurization (ODS) of dibenzothiophene prevailing in liquid fuel. Pure TiO2 was used as reference. The titania-based catalysts were characterized by chemical analysis, XRD, EDX and TEM. The titanium state as tetrahedral (in Ti-SBA-16 sample) or octahedral (in TiO2/SBA-16 sample) coordination surrounding in the silicate matrix was determined by XPS, UV–vis DRS, FTIR, Raman and XANES. We assessed the impact exerted on performance of different reaction variables, including (nature and amount of the active catalytic species, phase system, molar ratio of oxidant H2O2 and DBT, reaction temperature, nature of the substrate and reuse of catalysts). In addition, we carried out a kinetic study and the activation energy was determined. We achieved 90% of S removal from a 0.2wt.% dibenzothiophene solution at 60°C in less than 1h of reaction. The best catalytic results are obtained with high exposed surface of nanometric TiO2 species of TiO2/SBA-16 sample. The activated catalyst is very active in ODS reaction and can be reused four times with no loss in activity.