Preparation and characterization of Silicalite-1 zeolites with high manganese contents from mechanochemically pretreated reactants
Preparation and characterization of Silicalite-1 zeolites with high manganese contents from mechanochemically pretreated reactants
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DOI：
10.1039/c4ta06246a
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发表时间：
2015-03
影响因子：
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通讯作者：
T. Iida;Mitsutaka Sato;C. Numako;A. Nakahira;S. Kohara;T. Okubo;T. Wakihara
中科院分区：
文献类型：
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作者：
T. Iida;Mitsutaka Sato;C. Numako;A. Nakahira;S. Kohara;T. Okubo;T. Wakihara
采用机械力化学预处理法合成了高锰量的硅沸石-1分子筛。首先，将锰和硅源在行星球磨机中混合，得到由锰、硅和氧组成的复合材料。然后，对复合材料进行水热处理，使Silicalite-1沸石晶化。合成条件是在少量水的条件下，将复合材料直接转化为沸石晶体，同时防止锰浸出到水中，这可能会导致锰氧化物/氢氧化物物种的沉淀。X-射线荧光分析表明，所得产物的锰含量高达6.3摩尔%。通过X射线衍射、催化活性评价、漫反射紫外可见光谱、拉曼光谱和X射线吸收精细结构分析等表征技术，证实了机械力化学处理的重要性。我们的研究结果表明，采用机械化学预处理的方法可以得到骨架结构中含有各种杂原子的沸石，其含量是常规方法难以获得的。
Silicalite-1 zeolites with high manganese contents isomorphously incorporated within the framework were synthesized by using mechanochemical pretreatment. First, manganese and silica sources were mixed in a planetary ball mill to obtain a composite material comprised of Mn, Si, and O. The composite was subsequently hydrothermally treated to crystallize Silicalite-1 zeolites. The synthesis was performed using a condition with a small amount of water to directly convert the composite material into a zeolite crystal while preventing manganese from leaching into water, which may cause manganese oxide/hydroxide species to precipitate. X-ray fluorescence analysis showed that the obtained products displayed a high manganese content of up to 6.3 mol%. The importance of utilizing mechanochemical treatment was confirmed through a number of characterization techniques, such as X-ray diffraction, catalytic activity assessments, diffuse reflectance UV-vis spectroscopy, Raman spectroscopy, and X-ray absorption fine structure analysis. Our findings suggest that this procedure using mechanochemical pretreatment can produce zeolites with various heteroatoms within their framework structures at contents difficult to achieve through conventional methods.