Effect of Al content on phase transitions of zeolite MEL

被引:19
作者
Gonzalez, Gema [1 ]
Gomes, Maria E. [1 ]
Vitale, Gerardo [1 ]
Castro, German R. [2 ]
机构
[1] Inst Venezolano Invest Cient, Dpto Ingn, Lab Ciencia & Ing Mat, Caracas, Venezuela
[2] SpLine European Synchrotron Radiat Facil, Grenoble, France
关键词
MEL; Phase transition; Aluminum; Zeolite; ZSM-11; DENSITY-FUNCTIONAL THEORY; SOLID-STATE NMR; NEUTRON-DIFFRACTION; BRONSTED ACIDITY; ZSM-5; FRAMEWORK; CATIONS; SUBSTITUTION; TEMPERATURE; INTERGROWTH;
D O I
10.1016/j.micromeso.2008.12.027
中图分类号
O69 [应用化学];
学科分类号
081704 ;
摘要
The effect of the Si/Al ratio on the synthesis of zeolite MEL and their influence in the phase transitions that results has been studied. Depending on the AI content tetragonal (1-4m2) or MFl intergrowth have been observed. In samples with high AI content the formation of a new orthorhombic (Imm2) phase is proposed. Comparison of the experimentally determined powder X-ray data and the theoretically predicted powder X-ray data generated by using the models obtained by density functional theory (DFT) in the tetragonal and orthorhombic crystal systems of the zeolite with MEL structure has been carried out. (C) 2009 Elsevier Inc. All rights reserved.
引用
收藏
页码:26 / 33
页数:8
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