R. G. Rodríguez Avendaño^1*, J.A. de los Reyes¹, J.A. Montoya², T. Viveros²

¹ Universidad A. Metropolitana, Departamento de Ingeniería de Procesos Av. Rafael Atlixco 186, Col. Vicentina, Iztapalapa México, D.F. 09340; Área de Ingeniería Química, Universidad Autónoma Metropolitana-Iztapalapa, *rgra@xanum.uam.mx

² Instituto Mexicano del Petróleo, Programa de Simulación Molecular México, D.F.

Recibido: 10 de enero de 2006.
Aceptado: 13 de mayo de 2006.

Abstract

An experimental strategy was developed to obtain mesoporous SiO₂-ZrO₂ and SiO₂-TiO₂ mixed oxides via the sol-gel process. SiO₂-ZrO₂ materials involved the use of tetraethylorthosilicate (TEOS) and an inorganic Zr-containing salt source (nitrate). The ZrO₂ content, the synthesis pressure on the solids properties were studied and further modification of this type of procedure. In the case of the SiO₂-TiO₂ materials were synthesized by a sol-gel method using tetraethylorthosilicate (TEOS) and titanium isopropoxide, in a typical preparation. Both precursors were dried and calcined at 500°C. The solids were characterized by nitrogen physisorption, pyridine chemisorption, ²⁹Si Nuclear Magnetic Resonance, SEM and X-ray diffraction. Characterization of the solids revealed that mesoporous materials with very narrow pore diameter distribution were obtained when using the autoclave procedure from both mixed oxides. Surfaces areas and pore size distribution were a function of ZrO₂ and TiO₂ content. Differences in acidity as determined by pyridine adsorption were observed depending on the synthesis parameters.

Keywords: Modified Silica, Zirconia, Titania, mixed oxides; BET surface measurements.

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References

[1] J.A. Navio, M. Macias, G Colón., and J.M. Marinas, J. Catal. 161, 605 (1996).         [ Links ]

[2] Q. Zhuang, J.M. Miller, Appl. Catal. A: General, 209, L1 (2001).         [ Links ]

[3] B.M. Reddy, B. Chowdhury, P.G. Swirniotis, Appl. Catal. A: General 211, 19 (2001).         [ Links ]

[4] M. Aizawa, Y. Nosaka, N. Fujii, J. Non-Cryst Sol., 128, 77 (1991).         [ Links ]

[5] F. Gonella, G. Matter, and P. Mazzoldi, Chem. Matter, 11, 814 (1991).         [ Links ]

[6] R. Gomez, F.Tzompantzi, T. Lopez and O. Navaro, React. Kinet. Catal. Lett. 53, 245 (1994).         [ Links ]

[7] S. Damyanova, L. Petrov, M.A. Centeno, P. Grange, Appl. Catal. A: General 224, 271(2002).         [ Links ]

[8] K. Kamiya, S. Sakka and Tatemichi, J.Mater.Sci., 15, 1765 (1980).         [ Links ]

[9] W. Beier, A.A. Göktas, and G.H. Frischat, J. Non-Cryst. Sol., 121, 163 (1990).         [ Links ]

[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).         [ Links ]

[11] [Itoh, M., Hattori, H., and Tanabe, K., J. Catal. 35 225, (1974).         [ Links ]

[12] S.J. Gregg and K.S.W. Sing, Adsorption, Surface Area and Porosity, 2nd ed. (Academia Press, London) (1982) 195.         [ Links ]