Grafting of titanium alkoxides on high-surface SiO2 support: An advanced technique for the preparation of nanostructured TiO2/SiO2 catalysts

Cozzolino, M.; Serio, Martino Di; Tesser, Riccardo; Santacesaria, E.

doi:10.1016/j.apcata.2007.02.032

Cited by 81 publications

(58 citation statements)

References 21 publications

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“…The TiO 2 /AlOOH and TiO 2 /c-Al 2 O 3 supports were not subject to elemental analysis, but the presence of Ti element in Au/TiO 2 / AlOOH and Au/TiO 2 /c-Al 2 O 3 catalysts was verified and quantitatively measured by ICP-OES (Table 1). Although the Ti(IV) species from surface-sol-gel processing of titanium(IV) alkoxide has uncondensed hydroxyl groups, it is often denoted as TiO 2 for convenience [25,26,33,[36][37][38][39]. After loading gold, these four catalysts were tested either as synthesized or after pretreatment in O 2 -He at 500°C.…”

Section: Au/tio 2 /Alooh and Au/tio 2 /C-al 2 Omentioning

confidence: 99%

Novel Au/TiO2/Al2O3 · xH2O catalysts for CO oxidation

Yan

Mahurin

et al. 2007

Catal Lett

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Á xH 2 O (x = 0-3) catalysts were prepared by assembling gold nanoparticles on neat and TiO 2 -modified Al 2 O 3 , AlOOH, and Al(OH) 3 supports, and their catalytic activity in CO oxidation was tested either as synthesized or after on-line pretreatment in O 2 -He at 500°C. A promotional effect of TiO 2 on the activity of gold catalysts was observed upon 500°C-pretreatment. The catalyst stability as a function of time on stream was tested in the absence or presence of H 2 , and physiochemical characterization applying BET, ICP-OES, XRD, TEM, and 27 Al MAS NMR was conducted.

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Section: Au/tio 2 /Alooh and Au/tio 2 /C-al 2 Omentioning

confidence: 99%

Novel Au/TiO2/Al2O3 · xH2O catalysts for CO oxidation

Yan

Mahurin

et al. 2007

Catal Lett

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“…29 Fig . S3 (ESIw) shows the UV-vis spectra of (TiO x ) n /SBA-15 including the reference spectrum of anatase.…”

Section: à2mentioning

confidence: 99%

“…Fig. 2 presents the relationship between the ratio of the integrated areas of the n OH massif of each (VO 29 The asymptotic nature of the curve indicates the contribution of TiO-H stretching modes located at 3720 and 3670 cm À1 towards the integrated intensity of the n OH massif at higher Ti loadings. Clearly, the curve for the Ti/SBA-15 series represented in Fig.…”

mentioning

confidence: 99%

Topology of silica supported vanadium–titanium oxide catalysts for oxidative dehydrogenation of propane

Hamilton

Wolfram

Müller

et al. 2012

Catal. Sci. Technol.

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Two-dimensional vanadia and titania surface clusters were hosted on the walls of the hierarchical pore system of mesoporous silica SBA-15. The topology of the catalyst surface was varied by sequential grafting of vanadium and titanium alkoxides generating an extended library of mixed (VO x ) n -(TiO x ) n /SBA-15 catalysts. The surface of the catalysts was analyzed by FTIR, UV-vis, Raman, and NEXAFS spectroscopy. Electron microscopy, X-ray fluorescence, X-ray diffraction, and nitrogen adsorption have been applied to characterize chemical composition, micro-and meso-structure of the materials. Segregation of nano-crystalline vanadia and titania particles was excluded by UV-vis, Raman and NEXAFS spectroscopy. Monolayer coverage of titanium oxide surface species has been achieved in the range between 17 and 19 wt% Ti loading corresponding to 6-8 Ti atoms per nm cat 2 and Si/Ti ratios between 3.3 and 2.8. Up to a critical total metal loading, vanadia is grafted on both the silica surface and surface titania species yielding tetrahedrally coordinated vanadium oxo-species characterized by low nuclearity and moderate catalytic activity. A volcano-type dependency with respect to the propylene space-time yield has been observed in the oxidative dehydrogenation of propane. The maximum in productivity of propylene is attributed to a particular surface topology that is characterized by (VO x ) n islands embedded in a matrix of dispersed titania species forming an almost complete combined vanadia-titania monolayer on the silica surface.

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“…In the spectra of the samples coated once, the absorption wavelength was low, because titanium atoms were isolated on the silica walls 13) . With the coating time, the wavelength increased and after three-time coating the absorption wavelength was hardly changed.…”

Section: Ms-7 and Msmentioning

confidence: 99%

Preparation of Mesoporous Silica Uniformly Coated with Titania and Its Application to Hydrodesulfurization Catalyst

Satake

Okamoto

Sakayori

et al. 2017

J. Jpn. Inst. Energy

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Titania coating of mesoporous silicas (MSs) with different pore size was performed several times under thoroughly dried circumstances. When the pore size was 3 nm, the pore-plugging took place by only one time coating. On the other hand, for the pore size of 7 nm, a uniform coating with titania layer could be achieved until three time coating, and for that of 10 nm, the uniform coating without pore-plugging was obtained even after five time coating. These observations could be explained by the difference in the curvature of the silica pore walls.From various analyses and characterization, it was found that the titania coating was uniform and that three time coating was needed to coat all the silica walls and then possible coating mechanism was proposed.The MSs coated with titania were applied as the support of Mo catalyst for hydrodesulfurization (HDS) of sulfur-containing aromatics. The effect of titania coating on the dibenzothiophene HDS was not significant, but positive increase in activity was observed for 4,6-dimethyldibenzothiophene HDS. This increase was due to the enhancement of hydrogenation ability, in agreement with the results from the naphthalene hydrogenation. Moreover, it was found the formation of three-dimensional pores is very useful to increase the HDS activity.

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Grafting of titanium alkoxides on high-surface SiO2 support: An advanced technique for the preparation of nanostructured TiO2/SiO2 catalysts

Cited by 81 publications

References 21 publications

Novel Au/TiO2/Al2O3 · xH2O catalysts for CO oxidation

Novel Au/TiO2/Al2O3 · xH2O catalysts for CO oxidation

Topology of silica supported vanadium–titanium oxide catalysts for oxidative dehydrogenation of propane

Preparation of Mesoporous Silica Uniformly Coated with Titania and Its Application to Hydrodesulfurization Catalyst

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