Abstract
Zirconium (IV)-n-butoxide and tungstophosphoric acid (WP) were co-gelled at pH 3, 5 and 7 with HCl acid, C2H4O2 acid and NH4OH, respectively. Pyridine adsorption bands at 1610 and 1442 cm−1 corresponding to Lewis acidic sites were observed by FTIR spectroscopy. Acidity determined by ammonia thermodesorption shows values around 1100 μmol of NH3/g, which correspond to solids showing super acidity. It was found that the incorporation of WP to gelling zirconia delay the formation of tetragonal zirconia. Raman spectroscopy shows the stabilization of the Keggin structure on zirconia thermally treated at 400°C.
Similar content being viewed by others
References
T. Lopez, J. Navarrete, R. Gomez, H. Armendáriz, and F. Figueras, Appl. Catal. A: General 125, 217 (1995).
J.L. Sohn and H.J. Jang, J. Mol. Catal. 64, 349 (1991).
K. Arata, Advances in Catalysis 37, 165 (1990).
C.Y. Hsu, C.R. Heimbuch, C.T. Armes, and B.C. Gates, J. Chem. Soc., Chem. Comm. 1645 (1992).
Y. Amenomiya, Appl. Catal. 30, 57 (1987).
T. Iizuka, M. Kojima, and K. Tanabe, J. Chem. Soc., Chem. Comm. 638 (1983).
M. Misono, Catal. Rev. Sci. Eng. 29, 269 (1987), 30, 339 (1988).
X. Bokhimi, A. Morales, O. Novaro, M. Portilla, T. Lopez, F. Tzompantzi, and R. Gomez, J. Solid State Chem. 135, 28 (1998).
T. Lopez, R. Gomez, J.G. Hernández, E. López-Salinas, X. Bokhimi, A. Morales, J.L. Boldu, E. Muños, and O. Novaro, Langmuir 15, 5820 (1999).
E.P. Parry, J. Catal. 2, 374 (1963).
U.B. Mioc, R.Z. Dimitrijevic, M. Dividovic, Z.P. Nedic, M.M. Mitrovicand, and P.H. Colomban, J. Mater. Sci. 29, 3705 (1994).
P.D.L. Mercera, J.G. Van Ommen, E.B.M. Doesburg, A.J. Burgraaf, and J.R. Ross, Appl. Catal. 57, 127 (1990).
J.G. Hernández-Cortéz, T. López, R. Gomez, E. Torres Garcia, P.P. Lottici, and D. Bersani, J. Solid State Chem., to be published.
Rights and permissions
About this article
Cite this article
Hernández-Cortéz, J., López, T., Manríquez, M. et al. Thermally Induced Phase Transformation on 12-Tungstophosphoric Acid/ZrO2 Sol-Gel. Journal of Sol-Gel Science and Technology 26, 213–216 (2003). https://doi.org/10.1023/A:1020794914686
Issue Date:
DOI: https://doi.org/10.1023/A:1020794914686