Effect of support properties on sulfate promoted zirconium oxide
- Carnegie Mellon Univ., Pittsburgh, PA (United States)
We have examined the importance of the zirconium oxide support and identified the desired characteristics that yield a solid superacid upon sulfate impregnation. We compared different zirconium oxide supports, including our aerogel prepared from sol-gel chemistry and supercritical drying as well as commercially available zirconium oxides prepared by flame hydrolysis and precipitation. In addition to the traditional preparation technique of impregnating zirconium hydroxide, we were able to prepare a solid superacid by impregnating a calcined zirconium oxide. Using in situ diffuse reflectance infrared spectroscopy, X-ray diffraction, thermogravimetry, and n-butane isomerization, we have identified the important support features that allow for the formation of solid superacidity upon sulfate impregnation. Specifically, two required support characteristics are an amorphous or tetragonal crystal structure and the presence of hydroxyl groups bound to solitary zirconium atoms. Together they act to stabilize a supported sulfate structure that is necessary for superacidity.
- OSTI ID:
- 126277
- Report Number(s):
- CONF-950402--
- Country of Publication:
- United States
- Language:
- English
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