Morphology Changes of Transition-Metal-Substituted Aluminophosphate Molecular Sieve AlPO4-5 Crystals
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- 作者：Dayong Tian ; Wenfu Yan ; Xuejing Cao ; Jihong Yu ; Ruren Xu
- 刊名：Chemistry of Materials
- 出版年：2008
- 出版时间：March 25, 2008
- 年：2008
- 卷：20
- 期：6
- 页码：2160 - 2164
- 全文大小：553K
- 年卷期：v.20,no.6(March 25, 2008)
- ISSN：1520-5002
文摘
In this work, poly ethylene glycol (pEG) was used as a cosolvent to control the morphology of transition metal substituted aluminophosphate molecular sieve AlPO4-5 (AFI) crystals in the solvothermal reaction system of Al(OPri)3-H3PO4-TEA-Me-H2O-pEG (Me = Cr, Ti, Fe, V). In the presence of pEG molecules, the growth rate of the Me-AFI crystals along c-direction was significantly inhibited. With the increase of the volume ratio of pEG/H2O, the aspect ratio of hexagonal prismlike Cr-AFI crystals was gradually decreased and the tabletlike crystals were obtained. Further increasing the volume ratio of pEG/H2O resulted in the novel flowerlike morphology for Cr3+- and Fe3+-substituted AFI crystals and kiwi-fruit-like morphology for Ti4+ and V5+ substituted AFI crystals. Our studies revealed that the existence of pEG molecules and the isomorphic substitution of Al or P are important for the formation of these specific morphologies.