Mechanisms of formation of extraframework Al2O3 in zeolites
Por:
Alvarez L.J., Ramírez-Solís A., Giral P.B.
Publicada:
1 ene 1997
Resumen:
Extraframework alumina in zeolites is considered by some authors to play a crucial role in the establishment of their reactivity. Charge transfer molecular dynamics simulations (CTMD) in the microcanonical ensemble of zeolite Y confirmed that catalytically active sites in zeolites are produced by the presence of extraframework alumina, and indeed, that it also is necessary to stabilize the zeolite lattice. In this work we present a plausible model for the formation of extra-framework alumina based on the results of CTMD simulations of a Y zeolite with compensation sodium cations, and give the physicochemical arguments for the stabilization role that it plays. The simulated system consisted of 653 particles representing 165 silicon atoms, 414 oxygen atoms, 47 aluminum atoms, and 27 sodium atoms. Radial distribution functions, the i.r. spectrum, and the n.m.r. predictions reproduced fairly well the corresponding available experimental data. © Elsevier Science Inc. 1997.
Filiaciones:
Alvarez L.J.:
Laboratorio de Simulatión de Materielles, Directión General de Servitios de Cómputo Académico, Ciudad Universitaria, Coyoacán 04510, Mexico D.F, Mexico
Departamento de Química, Universidad Autónoma Metropolitana Iztapalapa, Avenida Michoacán y Purisima, Iztapalapa 04390, México D.F., Mexico
Ramírez-Solís A.:
Facultad de Ciencias, Universidad Autonoma del Estado de Morelos, Cuernavaca, 62210 Morelos, Mexico
Giral P.B.:
Laboratorio de Simulatión de Materielles, Directión General de Servitios de Cómputo Académico, Ciudad Universitaria, Coyoacán 04510, Mexico D.F, Mexico
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