The effect of sulfating on the crystalline structure of sol-gel zirconia nanophases
- UNAM, Mexico City (Mexico)
- UAM-I, Mexico City (Mexico)
Nanophases of sol-gel zirconia were prepared with HCl, C{sub 2}H{sub 4}O{sub 2} and NH{sub 4}OH as hydrolysis catalysts, and sulfated with H{sub 2}SO{sub 4}. They were analyzed by using X-ray powder diffraction, and their crystalline structure was refined by using the Rietveld method. All samples annealed below 300 C were amorphous. The non-sulfated samples crystallized around 350 C, while the sulfated samples crystallized around 600 C, when they started loosing sulfate ions. In the initial stage of crystallization, both the tetragonal and monoclinic nanophases coexisted, with the tetragonal as the main phase. Annealing the samples at higher temperatures transformed the tetragonal nanophase, stabilized by OH ions, into the monoclinic one.
- Sponsoring Organization:
- National Science Foundation, Washington, DC (United States)
- OSTI ID:
- 522285
- Report Number(s):
- CONF-961202--; ISBN 1-55899-361-4
- Country of Publication:
- United States
- Language:
- English
Similar Records
Perturbed-angular-correlation study of zirconias produced by the sol-gel method
Sol-gel synthesis and catalytic properties of sulfated zirconia