Materiales mesoporosos tipo hidrotalcita obtenidos por sol-gel asistido con irradiación de microondas y su evaluación catalítica y absorbente
Hydrotalcite-like mesoporous materials obtained by the sol-gel method with microwave radiation and his evaluation as catalists and sorbent
E. Ramos-Ramírez1*, N.L. Gutiérrez-Ortega2, G. del Angel-Montes3, F. Tzompantzi-Morales3, F. Acevedo-Aguilar1 y L.E. Mendoza-Puga2
1 Depto. de Química, Universidad de Guanajuato, Noria Alta s/n Guanajuato, Gto., C.P. 36050, éxico. * Corresponding author. E-mail: ramosre@ugto.mx Tel. (52) 473-73-2-00-06 ext. 6005, Fax. Ext. 6001.
2 Depto. de Ingeniería Civil, Universidad de Guanajuato, Juárez 77, Zona Centro, Guanajuato, Gto., C.P. 36000, México.
]]> 3 Depto. de Química, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco No.186, México D.F. C.P.09340, México.
Received April 8, 2015;
Accepted July 14, 2015.
Resumen
Con la finalidad de obtener materiales potencialmente útiles en la optimización de procesos catalíticos industriales y en remediación ambiental para la eliminación de desechos tóxicos, en este trabajo se presenta la síntesis de Materiales Mesoporosos Tipo Hidrotalcita por el método sol-gel asistido con irradiación de microondas a partir de alcóxidos metálicos de magnesio y aluminio con relaciones Mg/Al de 2 y 3. Los materiales obtenidos fueron caracterizados fisicoquímicamente para la determinación de sus propiedades estructurales, texturales y térmicas. Para la evaluación de la actividad catalítica y adsorbente de los materiales, se probó la reacción de descomposición de 2-propanol, y la remoción de cromo (VI) de soluciones acuosas. Los catalizadores obtenidos después del tratamiento térmico de los Materiales Mesoporosos Tipo Hidrotalcita a 400°C resultaron ser activos para la descomposición del 2-propanol dando una mayor selectividad a propeno que a acetona, con lo cual se confirma que los sólidos son preferentemente ácidos; además los Materiales Mesoporosos Tipo Hidrotalcita mostraron una buena capacidad de remoción de cromatos de soluciones acuosas con valores de 44 y 45mg de cromo (VI)/g de Material Mesoporos Tipo Hidrotalcita, mostrando el potencial que tienen dichos materiales para su empleo en procesos de remediación ambiental.
Palabras clave: materiales mesoporosos tipo hidrotalcita, método sol-gel, irradiación de microondas, hidrotalcitas ácidas, cromo (VI).
Abstract
]]> With the purpose of obtaining materials potentially useful in the optimization of catalytic industrial processes and in environmental remediation for the elimination of toxic waste, this work presents the synthesis of hydrotalcite like mesoporous materials by the sol-gel method with microwave irradiation from metallic alcoxides of magnesium and aluminium with relations Mg/Al of 2 and 3. The materials obtained were characterized for the determination of their structural, thermal and textural properties. For the evaluation of the catalytic and adsorption capacities of the materials, these were probed both in the reaction of 2-propanol decomposition, as well as in the removal of chrome (VI) from watery solutions; the above mentioned evaluation shows the potential that they have for their employment in processes of environmental remediation. The catalysts obtained on having thermal treated of hydrotalcite like mesoporous materials to 400°C turned out to be active for the decomposition of 2-propanol giving a greater selectivity to propylene that to propanone, with which the formation of preferably acidic compounds is confirmed. In addition the hydrotalcite like mesoporous materials a showed a good capacity for the removal of chromates from watery solutions with values of 44 and 45mg of chrome the (VI)/g of hydrotalcite like mesoporous materials.Keywords: hydrotalcite like mesoporous materials, sol-gel method, microwave irradiation, acid hydrotalcite chromium (VI).
DESCARGAR ARTÍCULO EN FORMATO PDF
Referencias
Alvarez-Ayuso, E., Nugteren, H.W. (2005) Purification of chromium (VI) finishing wastewaters using calcined and uncalcined Mg-Al-CO3-hydrotalcite. Water Resources 39, 2535-2542. [ Links ]
Aramendia, M.A., Borau, V., Jiménez, C., Marinas, J.M., Porras, A. y Urbano, F.J. (1994). Dehydration-dehydrogenation of 2-propanol as a model reaction for acid-base characterization of catalysts. Reaction Kinetics and Catalysis Letter 53, 397-404. [ Links ]
]]>Benito, P., Labajos, F.M., Rocha, J. y Rives, V. (2009). Microwaves and layered double hydroxides: a smooth understanding. Pure Application Chemical 81, 1459-1471. [ Links ]
Belloto, M., Rebours, B., Clause, O. y Lynch, J. (1996). A reexamination of hydrotalcite crystal chemistry. Journal of Physic Chemical 100, 8527-8534. [ Links ]
Casey, T.J. (1997). Unit Treatment Processes in water and wastewater engineering, Ed. John Wiley and Sons Ltd., USA, Pp. 113-114. [ Links ]
Cavani, F., Trifiro, F. y Vaccari, A. (1991). Hydrotalcite-type anionic clays: preparation. Properties and applications. Catalysis Today 11, 173-301. [ Links ]
Goh, K. H., Lim, T.T. y Dong, Z. (2008). Application of layered double hydroxides for removal oxyanions: a review. Water Research 42, 1343-1368. [ Links ]
]]>Jackson, S.D. y Hargreaves, J.S.J. (2009). Metal Oxides Catalysis, Editorial Wiley VCH, Germany, Pp 421-423. [ Links ]
Jitianu, M., Balasoiu, M. , Zaharescu, M., Jitianu, A.y Ivanov, A. (2000). Comparative Study of Sol-Gel and Coprecipitated Ni-Al Hydrotalcites. Journal of Sol-Gel Science and Technology 19, 453-457. [ Links ]
López, T., Bosch, P., Ramos, E., Gómez, R., Novaro, O., Acosta, D. y Figueras, F. (1996). Synthesis and characterization of sol-gel hydrotalcites structure and texture. Langmuir 12, 189-192. [ Links ]
Mills, S. J., Christy, A.G., Genin, J.M.R., Kameda, T. y Colombo, F. (2012). Nomenclature of the hydrotalcite super group: natural layered double hydroxides. Mineralogical Magazine 76, 1289-1336. [ Links ]
Miyata, S. (1983). Anion exchange properties of hydrotalcite like compounds. Clays and Clay Minerals 31, 305-311. [ Links ]
]]>Oh, J.M., Biswick, T.T. y Choy, J.H. (2009) Layered nanomaterials for green materials. Journal Materials Chemical 29, 2553-2563. [ Links ]
Othman, M.R., Helwania, Z., Martunusa, W. y Fernando, J. N. (2009). Synthetic hydrotalcites from different routes and their application as catalysts and gas adsorbents: a review. Applied Organometallic Chemistry 23, 335-346. [ Links ]
Pan, G.X., Ni, Z.M., Fang, C.P., Wang, L.G., Chen, J.B. (2005). Studies on adsorption of Cr (VI) from aqueous solutions onto Zn/Al-layered double hydroxides. Journal of Zhejiang University of Technology 33, 334-336. [ Links ]
Rahmani, A.R., Samadi, M.T., Noroozi, R. (2011). Hexavalent chromium removal from aqueous solutions by adsorption onto synthetic nano size valent iron (nZVI). World Academy of Science, Engineering and Technology 50, 80-83. [ Links ]
Ramos, E., López, T., Bosch, P., Asomoza, M. y Gómez, R. (1997). Sol-gel synthesis of hydrotalcite-like compounds. Journal of Sol-Gel Science and Technology 8, 437-442. [ Links ]
]]>Ramos, R.E y Gutiérrez, O.N.L. (2013). Materiales mesoporosos tipo hidrotalcita y sus aplicaciones en catálisis. En: Aplicaciones Selectas en Catálisis, (L. Cedeño y M.L. Hernández Eds), Pp. 133-171, Editorial Académica Española, España. [ Links ]
Reichle, W.T. (1986). Synthesis of anionic clay minerals (mixed metal hydroxides, hydrotalcite). Solid State Ionics 22, 135-141. [ Links ]
Reichle, W., Kang, S.Y. y Everhardt, D.S. (1986). The nature of the thermal decomposition of a catalytically active anionic clay mineral. Journal of Catalysis 101, 352-359. [ Links ]
Rojas, R. (2012). Layered double hydroxides applications as sorbent for environmental remediation. En Hydroxides: Synthesis, Types and Applications, (A. Calixto y D. AnalizEds), Pp. 40-73, Editorial Nova Science Publishers Inc. New York, USA. [ Links ]
Rosa, R. y Leonelli, C. (2013). Microwave -assisted reaction method for the intercalation of carboxilic acid anions into layered double hydroxides. Journal of Microwave Power and Electromagnetic Energy 47, 2-23. [ Links ]
]]>Rouquerol, F., Rouquerol, J. y Sing, K. (1999). Adsorption By Powders And Porous Solids: Principles Methodology And Applications, Editorial Academic Press, San Diego, USA. [ Links ]
Sharma, S.K., Kushwaha, P.K., Srivastava, V.K., Bhatt, S.D. y Jasra, R.V. (2007). Effect of Hydrothermal Conditions on Structural and Textural Properties of Synthetic Hydrotalcites of Varying Mg/Al Ratio. Industrial Engineering Chemical Research 46, 4856-4865. [ Links ]
Taylor, H.F.W. (1973). Crystal structures of some double hydroxide minerals. Mineralogical Magazine 39, 377-389. [ Links ]
Tichit, D., Rolland, A., Prinetto, F., Fetter, G., Martínez, M.J., Valenzuela, M.A., Bosch, P. (2002). Comparison of the structural and acidic-base properties of Ga- and Al- containing layered double hydroxides obtained by microwave irradiation and conventional aging of synthesis gels. Journal of Materials Chemistry 12, 3832-3838. [ Links ]
Trifiro, F. y Vaccari, A. (1996). Hydrotalcite anionic clays (Layered double hidroxides) En: Comprehensive Supramolecular Chemistry, (J.L. Atwood, J.E.D. Davies, D.D. Mac Nicol, F. Vogtle, F. Eds.), Pp. 251-291, Pergamon Press: Oxford, U.K. [ Links ]
]]>Wang, J.A., Chen, L.F., López, T., Gómez, R. y Novaro, O. (2003). Dehydrogenation and dehydration of isopropanol catalysed with sol-gel MgO-Al2O3 oxide. En Emerging fields in Sol-Gel Science and Technology (D. Avnir y M. Aergert Eds), Pp. 78-84.Kluwer Academic Publishers, Dordrecht, Holland. [ Links ]
Wang, Q., Huang, H., Guo, Z., Chen, L., Liu, Y., Chang, J., Zhong, Z., Luo, J. y Borgna, A. (2012). Morphology and composition controllable synthesis of Mg-Al-CO3 hydrotalcites by tuning the synthesis pH and the CO2 capture capacity. Applied Clay Science 55, 18-26. [ Links ]
Zheng, L.B., Ye, Y., Ji, S.S. (2004), Adsorption of chromium (VI) by Mg/Al- layered double oxides. Diq. Hua., 33, 208-214. [ Links ]
]]>