Effect of Synthesis Parameters on Sol–Gel Silica Modified by Zirconia
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An experimental strategy was developed to obtain mesoporous SiO2-ZrO2 mixed oxides via a sol–gel process, which involved the use of tetraethylorthosilicate (TEOS) and an inorganic Zr-containing salt. The effects of key process parameters on the properties of the materials were investigated, including the choice of Zr(IV) source (zirconium oxychloride or nitrate), the ZrO2 content and the synthesis pressure (i.e. ambient pressure or hydrothermal conditions). The resulting solids were dried, calcined at 500 °C, and characterized by nitrogen physisorption, pyridine chemisorption, 29Si Nuclear Magnetic Resonance and X-ray diffraction. The data revealed that mesoporous materials with very narrow pore diameter distribution were obtained when using the autoclave procedure from both zirconium nitrate and oxychloride salts. The surface areas and pore size distributions were a function of ZrO2 content. Differences in acidity, as determined by pyridine adsorption, were observed depending on the synthesis parameters.
Keywordsmodified silica zirconia X-ray powder diffraction BET surface measurements
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- 1.J.A. Navio, M. Macias, G Colón, and J.M. Marinas, J. Catal. 161, 605 (1996).Google Scholar
- 2.Q. Zhuang and J.M. Miller, Appl. Catal. A: General 209, L1 (2001).Google Scholar
- 3.B.M. Reddy, B. Chowdhury, and P.G. Swirniotis, Appl. Catal. A 211, 19 (2001).Google Scholar
- 4.T. Lopez, R. Gomez, and J. M. Ferrat, Chem. Lett. 1142 (1992).Google Scholar
- 5.F. Gonella, G. Matter, and P. Mazzoldi, Chem. Matter 11, 814 (1991).Google Scholar
- 6.R. Gomez, F.Tzompantzi, T. Lopez, and O. Navaro, React. Kinet. Catal. Lett. 53(2), 245 (1994).Google Scholar
- 7.S. Damyanova, L. Petrov, M.A. Centeno, and P. Grange, Appl. Catal. A: General 224, 271 (2002).Google Scholar
- 8.K. Kamiya, S. Sakka, and Tatemichi, J. Mater. Sci. 15, 1765 (1980).Google Scholar
- 9.W. Beier, A.A. Göktas, and G.H. Frischat, J. Non-Cryst. Solids 121, 163 (1990).Google Scholar
- 10.J. Ascensión Montoya de la Fuente “Propiedades estructurales y catalíticas de los sistemas de óxidos metálicos mixtos de Al2O3-TiO2”. Doctoral thesis UAM-I (1996).Google Scholar
- 11.S.J. Gregg and K.S.W. Sing, Adsorption, Surface Area and Porosity, 2nd ed. (Academic Press, London, 1982), p. 195.Google Scholar