Synthesis of large mordenite crystals with different aspect ratios
Synthesis of large mordenite crystals with different aspect ratios
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DOI：
10.1016/j.micromeso.2009.05.034
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发表时间：
2009-11
影响因子：
5.2
通讯作者：
Lei Zhang;A. Laak;P. Jongh;K. P. Jong
中科院分区：
文献类型：
--
作者：
Lei Zhang;A. Laak;P. Jongh;K. P. Jong
Large mordenite crystals hold interest for fundamental research on separation and catalysis as well as emerging applications such as functional devices. A number of methods are now available to obtain large mordenite crystals. However, it still remains a challenge to synthesize large and uniform crystals with a desired aspect ratio. Moreover, a detailed description of a reproducible synthesis method is still lacking. We report here large and uniform mordenite crystals (27×36×30μm3) with an accessible micropore volume of 0.17cm3/g that can be reproducibly synthesized. The synthesis procedure is described in detail. The effects of synthesis parameters on mordenite morphology (size and aspect ratio of the crystals), such as silicon precursors, H2O content, Na2O/SiO2/Al2O3ratios, alcohol additives, have been systematically studied. Large mordenite crystals (up to 85μm) with prismatic shape were formed from a dense synthesis gel with high SiO2/Al2O3and Na2O/SiO2ratios, or by adding alcohol additives. Moreover, the aspect ratio of the large crystals was controlled by finely altering the above synthesis parameters. In the presence of an excess amount of alcohol, hollow and core–shell mordenite crystals were formed.
