Full Compositional Flexibility in the Preparation of Mesoporous MFI Zeolites by Desilication
Full Compositional Flexibility in the Preparation of Mesoporous MFI Zeolites by Desilication
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DOI：
10.3929/ethz-a-010788858
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发表时间：
2011-06
影响因子：
3.7
通讯作者：
D. Verboekend;S. Mitchell;M. Milina;J. Groen;J. Pérez–Ramírez
中科院分区：
文献类型：
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作者：
D. Verboekend;S. Mitchell;M. Milina;J. Groen;J. Pérez–Ramírez
我们证明，在酒精培养基中的设计是一种合适的合成方法，可以通过系统筛选两种基础浓度的影响（0.1-1.8 MaOH），引入MFI沸石中的晶体内中膜性。和Si/Al比率（10-1000）在处理过的沸石的性质上，我们透露，可以在Si/Al范围内实现有效的中源性引入（> 200 m2 G – 1） 12–200。在先前确定的SI/AL范围为25-50范围内，我们确定了随后的酸治疗的至关重要的作用在低Si/Al比率的情况下，碱性处理的样品（<20）。
We demonstrate that desilication in alkaline medium is a suitable post-synthetic method to introduce intracrystalline mesoporosity in MFI zeolites independent of the Si/Al ratio in the parent material. By systematic screening of the influence of both base concentration (0.1–1.8 M NaOH) and Si/Al ratio (10–1000) on the properties of the treated zeolites, we reveal that effective mesoporosity introduction (>200 m2 g–1) may be achieved in the Si/Al range of 12–200. The use of descriptors like the “indexed hierarchy factor” and the “desilication efficiency” enable the rational categorization of the solids obtained. The highest desilication efficiencies, estimated by correlating the introduced mesoporosity with the yields after NaOH treatment, are obtained in the previously established Si/Al range of 25–50. We identify the crucial role of a subsequent acid treatment for removing amorphous Al-rich debris from alkaline-treated samples in the case of low Si/Al ratios (<20). The latter acid wash uncovers the compl...