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ZrSBA-15 support with Si/Zr = 20 containing majority of Zr in framework positions is synthesized by direct addition of Zr to the synthetic mixture. Various catalysts containing 2–12 molybdenum loading were prepared by incipient wetness impregnation. Using 8 wt% Mo catalysts Co and Ni promoted catalysts were prepared with 1–5 wt% promoter loading. All the Mo, CoMo, NiMo catalysts were characterized by N2 adsorption–desorption, low angle and wide angle XRD, temperature programmed reduction (TPR) and oxygen chemisorption on sulfide catalysts. The catalytic activities for thiophene HDS, cyclohexene HYD were evaluated on sulfide catalysts at 400 °C. The oxygen uptakes and catalytic activities for HDS and HYD passed through a maximum at 8 wt% loading. The H2/Mo ratios obtained as a function of Mo loading also passed through a maximum at the same temperature. The promoted catalyst showed maximum activity at 3 wt% loading for both the functionalities. These results will be discussed in the light of characterization results in terms of reducibility, dispersion and anion vacancy variation with Mo and promoter loading.

Ordered mesoporous material SBA-15 was synthesized and used as a support for the preparation of molybdenum sulphide catalysts through precipitation from homogeneous solution (PFHS) technique with the Mo content varying from 2–12 wt%. The prepared catalysts were evaluated for thiophene hydrodesulphurization catalytic activities at 400°C. Catalysts prepared through PFHS method resulted in highly dispersed MoS2 catalysts, which were inferred from powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), low temperature oxygen chemisorptions (LTOC) and BET surface area analysis. The relationship between XPS intensity ratio, oxygen chemisorption and catalytic activities is discussed in terms of highly dispersed nano particles of MoS2 and its consequence in accommodating more promoted atoms at the edge sites.

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 12 wt.% Mo loading. The surface area analysis indicated that molybdenum is highly dispersed as monolayer 12 wt.% 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 12 wt.% 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.

SBA-15 containing various amount (10–50 wt.%) of highly dispersed ZrO 2 is prepared using urea hydrolysis method. The sulfated zirconia (ZrO 2 ) in SBA-15 catalysts were prepared using these materials. The materials were characterized by XRD, BET surface area, TEM, TGA, acidity measurements using in situ IR pyridine adsorption, sulfate content and catalytic activities were studied for cumene cracking and esterification of cyclohexanol. The Bronsted acidity, catalytic activity for cumene cracking and esterification and sulfate content were found to pass through a maxima where ZrO 2 loading is 35 wt.%. The 35SZ-SBA catalysts exhibited 6.4 times higher activity for cumene cracking compared to the bulk SZ catalysts. The relationship between acidity, sulfate content and catalytic activity are discussed in the light of existing knowledge on sulfated zirconia.

Al-SBA-15 of varying Si/Al ratios in the range 11.4–78.4 was synthesized using tri-block copolymer P123. The calcined materials were examined by XRD, pore size distribution, surface area, 27 Al NMR spectroscopy. The acidity and acid strength distribution were studied using microcalorimetric adsorption of NH 3 . The acidic properties were also examined by cumene cracking reaction as a function of Si/Al ratios. Systematic variation of acidity and activity was observed as a function of Si/Al ratio. The initial heats of NH 3 adsorption correlated well with activity indicate that acid sites with Δ H > 100 kJ/mole is responsible for cumene cracking activity. Linear correlations were obtained with total acidity and cumene cracking activities. The tetrahedral aluminum was found to be responsible for the observed acidities and catalytic activities.

SBA-15 and ZrO 2 (10–50 wt.%) containing SBA-15 mesoporous materials were prepared by direct and post-synthesis methods. Characterization using low angle XRD, pore size distribution, CO 2 chemisorption indicate that hexagonal mesoporous structure is retained even after ZrO 2 addition (25 wt.%). Mo, CoMo and NiMo catalysts prepared using these supports were examined by XRD, oxygen chemisorption, temperature programmed reduction (TPR). The catalysts were tested for hydrodesulfurization (HDS) of thiophene and hydrogenation (HYD) of cyclohexene. HDS of thiophene for 8%Mo, 3%Co8%Mo, and 3%Ni8%Mo increases with increasing ZrO 2 loading in SBA-15 up to 25 wt.%. Oxygen chemisorption and TPR hydrogen consumption indicated that the molybdenum dispersion and anion vacancies, and catalytic activities are significantly influenced by ZrO 2 content in Zr-SBA-15. A comparison indicated that TiO 2 -SBA-15, ZrO 2 -SBA-15 supported CoMo catalysts show higher activities for hydrodesulfurization.

High surface area, ordered mesoporous SBA-15 and Al-SBA-15 were synthesized using published procedures and used as support for Mo and W catalysts promoted with Co and Ni. The molybdenum loading was varied on Al-SBA-15 from 2 to 12 wt %, and Co or Ni loading was varied on 8%Mo/Al-SBA-15 from 1 to 5 wt %. The support and catalysts were characterized by X-ray diffraction (XRD), Barett−Joyner−Halenda (BJH) pore-size distribution, Brunauer−Emmett−Teller (BET) surface area, Fourier transform infrared (FT-IR), temperature-programmed reduction (TPR), and oxygen chemisorption. The characterization results indicated that hexagonal mesoporous structure is retained on Mo, CoMo, and NiMo catalysts. The TPR studies indicated that there are significant differences in Mo reducibilities and reducible species that are present on SBA-15 and Al-SBA-15 supported catalysts. The catalytic activities for thiophene, hydrodesulfurization (HDS), and cyclohexene hydrogenation (HYD) were carried out as a function of Mo and CoMo or Ni...

H-β-zeolite-supported tungsten sulfide catalysts with W loading varying between 10 and 25 wt % were prepared and characterized by BET surface area, pore size distribution in micro- and mesopore regions, in situ microcalorimetric ammonia adsorption, and oxygen chemisorption at low temperatures on sulfided catalysts. The thiophene HDS, cyclohexene hydrogenation (HYD), and cumene hydrocracking (HCK) reactions were carried out on sulfided catalysts. The differential heat curves and acid strength distributions indicated that sulfiding and WS2 content have a profound influence on the acidic properties of these catalysts. It was concluded that zeolite and WS2 both contribute to the acidic properties of the catalysts. There exists a correlation between strong acid sites and HCK activity. The relation between initial heat of adsorption and HCK activity suggested that acid sites ≥100 kJ/mol are involved in cumene hydrocracking on these catalysts.

Catalysts containing 2-12 wt % Mo and 1-5 wt % Co or Ni were prepared using commercial H-β-zeolite as a support. The support as well as various catalysts were characterized by X-ray diffraction (XRD), BET surface area, temperature-programmed reduction (TPR), and in situ oxygen chemisorption in the sulfided state. The XRD studies indicated that the crystallinity of β-zeolite decreases rapidly at higher loadings of molybdenum, and there is no evidence for the presence of crystalline Mo phases below 10 wt % Mo loading. At higher loadings, however, MoO 3 /MoS 2 may be present in small quantities. The BET surface area analysis indicated that molybdenum is well-dispersed up to 6 wt % Mo loading in both oxide and sulfide states. The oxygen uptakes increased up to 6 wt % Mo and then decreased at higher loadings. The crystallite sizes evaluated by oxygen chemisorption are small, indicating that MoS 2 is well-dispersed on the support up to 6 wt % Mo. The TPR results indicated that a Co or Ni promoter helps decrease the temperature of the Mo reduction. TPR results indicated that two molybdenum phases with differing reduction behavior exist before and after 6% Mo loading. Catalytic activities for HDS, HYD, and HCK followed the same trend as oxygen uptake. A comparison with γ-Al 2 O 3 indicated that the β-zeolite support imparts superior HYD activities in Mo, CoMo, and NiMo catalysts. Y-zeolite catalysts exhibit higher HDS activities but lower HYD activities than β-zeolite-supported catalysts.

SBA-15 and Al-SBA-15 of varying Si/Al ratios (10–40) were synthesized by well-known procedures. Characterization using XRD, pore size distribution, 27 Al NMR confirmed that hexagonal mesoporous structure is obtained and majority of Al is in tetrahedral positions. Mo, CoMo and NiMo catalysts prepared using these supports were examined by XRD, oxygen uptakes in sulfided state and temperature programmed reduction (TPR). The catalysts were tested for hydrodesulfurization (HDS) of thiophene and hydrogenation of cyclohexene. Systematic variation of oxygen chemisorption and catalytic activities were observed as a function of Si/Al ratio. The systematic variation of activities, oxygen chemisorption and TPR hydrogen consumption of Mo indicated that the molybdenum dispersion and anion vacancies, and catalytic activities are significantly influenced by support Al content. Compared to SBA-15, Al-SBA-15 supported Mo, CoMo and NiMo catalysts show outstanding activities for hydrogenation.

FSM-16 (Folded Sheet Silica) supported catalysts could accommodate 12 wt% Mo (18% MoO(3)) as a monolayer with higher dispersion than any other silica support; these catalysts showed outstanding HDS and HYD activities compared to gamma-Al(2)O(3), amorphous silica, and other mesoporous silica supported catalysts.