Metakaolin as a reagent for the assembly of mesoporous aluminosilicates with hexagonal, cubic and wormhole framework structures from proto-faujasitic nanoclusters
Metakaolin as a reagent for the assembly of mesoporous aluminosilicates with hexagonal, cubic and wormhole framework structures from proto-faujasitic nanoclusters
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DOI：
10.1039/b410337h
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发表时间：
2004-11
影响因子：
--
通讯作者：
Yu Liu;T. Pinnavaia
中科院分区：
文献类型：
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作者：
Yu Liu;T. Pinnavaia
通过高岭土粘土的热脱羟基化形成的偏高岭土已被证明是用于制备八面沸石纳米团簇的有效试剂，所述八面沸石纳米团簇用于骨架结合到Si/Al比在5.6-1.6范围内的六方、立方和虫孔铝硅酸盐中间相中。对于每个介观结构，观察到具有60 ppm的27 Al NMR化学位移的单个四面体铝位点，这表明将原沸石纳米团簇并入骨架壁中。与由常规前体组装的铝硅酸盐介观结构不同，在550 °C下煅烧时，对于介观结构没有观察到骨架脱铝。结果表明，偏高岭土是一种有前途的低成本前驱体，用于工业规模生产高品质的铝硅酸盐中间相。
Metakaolin, formed through the thermal de-hydroxylation of kaolin clay, has been shown to be an effective reagent for the preparation of faujasitic zeolite nanoclusters for framework incorporation into hexagonal, cubic and wormhole aluminosilicate mesophases with Si/Al ratios in the range 5.6–1.6. Single tetrahedral aluminum sites with 27Al NMR chemical shift of 60 ppm are observed for each mesostructure, which is indicative of the incorporation of the protozeolitic nanoclusters into the framework walls. Unlike aluminosilicate mesostructures assembled from conventional precursors, no framework de-alumination was observed for the mesostructures upon calcination at 550 °C. The results suggest that metakaolin is a promising low-cost precursor for the industrial scale production of high quality aluminosilicate mesophases.