Partial Transformation of MCM-41 Material into Zeolites: Formation of Nanosized MFI Type Crystallites
Partial Transformation of MCM-41 Material into Zeolites: Formation of Nanosized MFI Type Crystallites
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DOI：
10.1021/cm001127q
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发表时间：
2001-02
影响因子：
8.6
通讯作者：
M. J. Verhoef;P. Kooyman;J. C. Waal;M. Rigutto;Andrew J. Peters;H. Bekkum
中科院分区：
文献类型：
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作者：
M. J. Verhoef;P. Kooyman;J. C. Waal;M. Rigutto;Andrew J. Peters;H. Bekkum
通过对MCM-41孔壁的部分重结晶，开发了一种潜在的新型催化材料。通过四丙基氢氧化铵浸渍MCM-41，然后水热处理来诱导再结晶。该过程导致形成约3 nm的小颗粒，这可以用TEM观察到。这些颗粒的形成类似于ZSM-5形成的第一阶段的事实和使用模板材料（其也经常应用于ZSM-5的合成）的事实表明3 nm颗粒具有ZSM-5结构。此外，重结晶的MCM-41上的13 C NMR显示TPA的甲基信号的分裂，其也已知存在于合成的ZSM-5中。在煅烧重结晶的材料之后，不能再观察到小的微晶，尽管IR测量显示仍然存在一些ZSM-5样酸性。为了保护ZS，应开发其他温和的煅烧路线。
A new potentially catalytic material has been developed by partial recrystallization of the porewall of MCM-41. Recrystallization is induced by impregnation of MCM-41 with tetrapropylammonium hydroxide followed by a hydrothermal treatment. This procedure resulted in the formation of small particles of approximately 3 nm, which can be observed with TEM. The fact that the formation of these particles resembles the first stages of ZSM-5 formation and the fact that a templating material is used, which is also frequently applied in the synthesis of ZSM-5, suggest that the 3 nm particles have a ZSM-5 structure. Furthermore, 13C NMR on recrystallized MCM-41 shows a split-up of the methyl signal of TPA, which is also known to be present in as-synthesized ZSM-5. After calcination of the recrystallized material the small crystallites could no longer be observed, although IR measurements show still some ZSM-5-like acidity to be present. Other, milder calcination routes should be developed in order to preserve the ZS...