Incorporation of boron into nano-size MFI zeolite structure using a novel microwave-assisted two-stage varying temperatures hydrothermal synthesis
Incorporation of boron into nano-size MFI zeolite structure using a novel microwave-assisted two-stage varying temperatures hydrothermal synthesis
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DOI：
10.1016/j.micromeso.2010.07.011
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发表时间：
2010-12
影响因子：
5.2
通讯作者：
Mohsen Mehdipourghazi;A. Moheb;Hossein Kazemian
中科院分区：
文献类型：
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作者：
Mohsen Mehdipourghazi;A. Moheb;Hossein Kazemian
采用微波辅助“两段变温”水热合成方法，研究了三价硼在MFI分子筛结构中的同构取代。考察了模板浓度、时效/搅拌时间、Si/B比、第二阶段时间和温度对分子筛尺寸、形貌和产率的影响。第一阶段沸石前驱体在80℃条件下成核成熟90min，第二阶段在120 ~ 175℃条件下结晶30 ~ 60min。用SEM表征了颗粒的均匀性和形貌，用FT-IR和XRD测试结果记录了样品的框架振动谱和结晶度。在120°C和175°C条件下，晶粒尺寸和粉末回收率分别为75 ~ 410nm和26.9% ~ 100% （w/w）。在140℃下结晶60min后，MFI相结晶度达到100%。
The isomorphous substitution of trivalent boron in MFI zeolite structure by applying a novel microwave-assisted “two-stage varying temperature” hydrothermal synthesis method was investigated in this study. The effects of template concentration in the batch composition, aging/stirring time, Si/B ratio and second stage time and temperature on the size, morphology and zeolite formation yield were of interest. At the first stage, nucleation and maturation of zeolite precursors was carried out at 80°C for 90min, whereas, the crystallization was done during the second stage at temperature range of 120–175°C and crystallization time in the range of 30–60min. The homogeneity and morphology of particles were specified by SEM and the framework vibration spectra and crystallinity of the samples were recorded by FT-IR and XRD test results. Crystallites size and powder recovery varied from 75 to 410nm and from 26.9% to 100% (w/w), respectively for 120 and 175°C. Also, crystallinity of MFI phase reached 100% after 60min crystallization at 140°C.