Comparative study of aluminosilicate glass and zeolite precursors in terms of Na environment and network structure
Comparative study of aluminosilicate glass and zeolite precursors in terms of Na environment and network structure
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DOI：
10.1016/j.micromeso.2018.05.006
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发表时间：
2018-11
影响因子：
5.2
通讯作者：
Hiroki Yamada;Sohei Sukenaga;K. Ohara;Chokkalingam Anand;M. Ando;H. Shibata;T. Okubo;T. Wakihara
中科院分区：
文献类型：
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作者：
Hiroki Yamada;Sohei Sukenaga;K. Ohara;Chokkalingam Anand;M. Ando;H. Shibata;T. Okubo;T. Wakihara
揭示沸石非晶态前驱体的结构特征是阐明沸石形成机理的重要研究课题。为了了解沸石前体的综合结构特征，本研究将前体与具有相似成分的玻璃进行了比较。通过结合高能X射线全散射法、23Na-MQ-MAS-NMR和反向蒙特卡罗模拟，我们揭示了FAU型沸石及其前驱体和具有相似成分的玻璃之间的结构差异。对于FAU型沸石的结晶行为，对分布函数和NMR分析表明，Na的环境在结晶过程中逐渐变得有序。此外，还确认了大的铝硅酸盐环的弛豫。沸石前驱体和玻璃的比较阐明了 Na-O 距离和环分布的差异，模拟模型支持了这些见解。
Revealing structural features of the amorphous precursor of zeolite is an important research topic for elucidating formation mechanism of zeolites. To understand the zeolite precursor's comprehensive structural features, this study compared the precursor with the glass possessing similar compositions. By combining the high-energy X-ray total scattering method,23Na-MQ-MAS-NMR, and reverse Monte Carlo simulation, we revealed structural differences among FAU-type zeolites, their precursors, and glass with similar compositions. As for crystallization behavior of FAU-type zeolite, pair distribution function and NMR analyses revealed that the environment of Na became gradually ordered during the crystallization. In addition, relaxation of large aluminosilicate rings was also confirmed. Comparison of the zeolite precursor and the glass clarified differences in Na–O distances and ring distributions, and simulation modeling supported these insights.