K and Ca exchange behavior of zeolite A
K and Ca exchange behavior of zeolite A
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DOI：
10.1016/j.micromeso.2011.09.025
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发表时间：
2012-03-15
影响因子：
5.2
通讯作者：
Fischer, Reinhard X.
中科院分区：
文献类型：
--
作者：
Luehrs, Hanna;Derr, Jewgenij;Fischer, Reinhard X.
沸石-A（[Na_（11.8）Al_（11.8）Si_（12.2）O_（48）中心点26 H_2 O]（8），LTA，Na-A）的粉末样品完全进行Ca和K交换。生产了端元Na-、Ca-和K-沸石A之间的几种组合物。结合X射线粉末衍射，包括晶格参数的细化，在空间群Fm（3）棒c，能量色散X射线光谱，和热重分析的结果。Rietveld精修进行了三个富钠样品中的钙交换系列。描述了晶格常数a与Ca和K含量的线性关系以及水与Ca和K含量的关系。Ca和K含量。晶格参数a随着Ca和K含量的增加而减小，Ca交换形式的范围为24.62至24.46埃，K交换形式的范围为24.63至24.58埃。更高的Ca含量导致更高量的水结合在沸石中，范围为25（Na-A）至28（Ca-A）分子/分子式单位（m.p.f.u.）而K交换形式的水含量变化约为23.5 +/-1.0m.p.f.u.。与K含量无直接相关性，但显著低于26 m.p.f.u.的Na-A起始材料。Ca和K含量可由点阵参数a通过线性回归估计。(c)2011 Elsevier Inc. All rights reserved.
Powdered samples samples of zeolite-A ([Na11.8Al11.8Si12.2O48 center dot 26 H2O](8), LTA, Na-A) were completely Ca and K exchanged. Several compositions between the end members Na-, Ca-, and K-zeolite A were produced. Combined results from X-ray powder diffraction including lattice parameter refinements in space group F m (3) over bar c, energy dispersive X-ray spectroscopy, and thermal gravimetric analyses are presented. Rietveld refinements are performed for the three Na-rich samples in the Ca exchange series. The linear dependence of the lattice parameter a on the Ca and K contents is described as well as the relationship between water. Ca and K content. The lattice parameter a decreases with increasing Ca and K content, ranging from 24.62 to 24.46 angstrom for the Ca-exchanged forms and from 24.63 to 24.58 angstrom for the K-exchanged forms. Higher Ca content results in a higher amount of water incorporated in the zeolite, ranging from 25 (Na-A) to 28 (Ca-A) molecules per formula unit (m.p.f.u.) whereas the water content in the K-exchanged forms varies about 23.5 +/- 1.0 m.p.f.u. not directly correlated with the K contents but significantly lower than the 26 m.p.f.u. of the Na-A starting material. The Ca and K contents can be estimated from lattice parameter a by linear regression. (c) 2011 Elsevier Inc. All rights reserved.