Vanadyl tert-butoxy orthosilicate, OV[OSi(O{sup t}Bu){sub 3}]{sub 3}: A model for isolated vanadyl sites on silica and a precursor to vanadia-silica xerogels
The single source precursor OV[OSi(O{sup t}Bu){sub 3}]{sub 3} was synthesized in high yield from OVCl{sub 3} and HOSi(O{sup t}Bu){sub 3}. This tri(alkoxy)siloxy complex was characterized by {sup 1}H, {sup 13}C, {sup 29}Si, and {sup 51}V NMR, FT-Raman, FT-IR, EXAFS, and UV-vis spectroscopies and by mass spectrometry. In the Raman spectrum of OV[OSi(O{sup t}Bu){sub 3}]{sub 3}, V=O (1038 cm{sup {minus}1}) and V-O (651, 674, and 705 cm{sup {minus}1}) vibrations were observed. The {sup 51}V NMR shift was observed at {minus}777 ppm and the {sup 29}Si NMR resonance appears at {minus}98 ppm. Thermolysis in n-octane at 180 C resulted in formation of a green gel which upon drying in air formed a xerogel with a surface area of 320 m{sup 2} g{sup {minus} 1}, an average pore size of 140 {angstrom}, and a total pore volume of 2.25 cm{sup 3} g{sup {minus}1}. The calcined xerogel is similar to bulk V{sub 2}O{sub 5} in catalytic performance for propane oxidative dehydrogenation.
- Research Organization:
- Univ. of California, Berkeley, CA (US)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 20001163
- Journal Information:
- Chemistry of Materials, Vol. 11, Issue 10; Other Information: PBD: Oct 1999; ISSN 0897-4756
- Country of Publication:
- United States
- Language:
- English
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