Interaction of titanium isopropoxide with surface hydroxyls on silica

Journal Article · Mon Jan 31 23:00:00 EST 1994 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1994.1068· OSTI ID:7046015

Srinivasan, S; Datye, A K; Smith, M H ^[1]; Peden, C H.F. ^[2]

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1. Univ. of New Mexico, Albuquerque, NM (United States)
2. Sandia National Labs., Albuquerque, NM (United States)

Six different silicas, (two aerosils, a hydrophobic aerosil, a silica gel, and Stoeber spheres) pretreated at 423 K in vacuum were impregnated with Ti-(O-i-Pr)[sub 4] in a N[sub 2] atmosphere and the excess alkoxide washed away in an inert environment. Infrared spectroscopy showed significant differences in the relative proportions of isolated and H-bonded surface hydroxyls on these silicas. The silicas that had a higher proportion of H-bonded hydroxyls picked up a greater amount of titania under this impregnation procedure. Using the route described above, the upper limit of loading appeared to be [approximately]3.0 Ti/nm[sup 2] on Stoeber silica spheres, whose distinguishing feature was that the surface contained exclusively H-bonded hydroxyls. In situ infrared spectroscopy was also used to probe the interaction of the titanium alkoxide with the isolated as well as the H-bonded hydroxyls. On the basis of all of these experiments, they conclude that the hydroxyl groups that are capable of H-bonding with neighboring hydroxyls are the preferred adsorption sites, while the isolated hydroxyls are inert, at least at room temperature. 27 refs., 6 figs., 1 tab.

• OSTI ID: 7046015
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 145:2; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ABSORPTION SPECTROSCOPY
ADSORPTION
ALKOXIDES
CHALCOGENIDES
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
SILICA
SILICON COMPOUNDS
SILICON OXIDES
SORPTION
SORPTIVE PROPERTIES
SPECTROSCOPY
SURFACE PROPERTIES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS