Catalytic functionalities of FSM-16 ordered mesoporus silica supported molybdenum hydroprocessing catalysts

• Published in: Catalysis today 2012-12, Vol.198 (1), p.263-269
• Main Authors: Garg, Shelu, Soni, Kapil, Kumar, Manoj, Bhaskar, Thallada, Gupta, J.K., Rao, K.S. Rama, Dhar, G. Murali
• Format: Article
• Language: English
• Subjects: Catalysis; catalysts; catalytic activity; Chemistry; Colloidal state and disperse state; Dispersion; Exact sciences and technology; FSM-16; General and physical chemistry; Hydrocracking; hydrogenation; Mesoporous support; molybdenum; oxygen; Porous materials; silica; surface area; Surface physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; thiophene; transmission electron microscopy; Zero point charge
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2012.05.049

[Display omitted] ► FSM-16 could accommodate up to 12wt.% Mo(18wt.% MoO3) loading and high dispersion of oxide state. ► The SA, OC indicated that MoO3 is dispersed as a monolayer up to 12wt.% Mo and carried into the sulfide state. ► High amount of MoS2 dispersed on FSM-16 showed higher HDS of thiophene, HYD of cyclohexene and HCK of cumene activities. ► Oxygen chemisorptions is not specific to any functionality but measures general state of dispersion of MoS2. ► An excellent correlation obtained between OC & HDS/HCK/HYD suggests that all these involve anion vacancies in this active site structure (MoS2 surface). Well ordered FSM-16 mesoporous material was synthesized by using established procedures. Mo, CoMo, NiMo catalysts were prepared using this FSM-16 mesoporous material as support. The support and the catalysts were characterized by XRD, Transmission electron microscopy (TEM) pore size distribution measurements. The XRD, TEM and pore size distributions indicated that the ordered mesoporous structure is obtained and retained after Mo and Co(Ni) additions. The wide angle XRD measurement indicated that molybdenum is highly dispersed up to 12wt.% Mo loading. The surface area analysis indicated that molybdenum is highly dispersed as monolayer 12wt.% Mo zero point charge (ZPC) and XRD measurements confirmed the same. The oxygen chemisorption measurements indicated that the higher dispersion in the oxide state is carried into sulfided state also. The thiophene HDS, cyclohexene hydrogenation and cumene cracking activities all showed that maximum activity is obtained at 12wt.% Mo loading. Excellent correlations are obtained between oxygen uptakes and catalytic activities. These studies indicated that MoS2 phase has significant cracking functionality. The correlations with catalytic functionalities are discussed in the light of characterization results.