Characterization of Defects and Surface Structures in Microporous Materials by HRTEM, HRSEM, and AFM
Characterization of Defects and Surface Structures in Microporous Materials by HRTEM, HRSEM, and AFM
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通过 HRTEM、HRSEM 和 AFM 表征微孔材料中的缺陷和表面结构
DOI：
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发表时间：
2004
影响因子：
2.8
通讯作者：
R. Reichelt
中科院分区：
文献类型：
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作者：
G. Gonzalez;W. Stracke;Z. López;U. Keller;Andrea Ricker;R. Reichelt
采用高分辨透射电镜（HRTEM）、高分辨扫描电子显微镜（SEM）、原子力显微镜（AFM）、X射线衍射（XRD）和电子衍射（EDS）等手段对MFI、MEL分子筛及MFI/MEL共生体系进行了研究。所有三种沸石均由尺寸在约0.5 μm至5 μm范围内的单个颗粒组成。颗粒习性从相当立方形变化到几乎球形，具有许多中间习性。典型地，这三种沸石的颗粒由许多单独的嵌段组装，这些嵌段在尺寸上从约25 nm至140 nm不同，并且在形状上从非常常见的几乎矩形（对于MFI、MEL和MFI/MEL）到有时为圆形或不规则习惯（主要对于MFI/MEL）不同。估计表明，约104至大于106个密集堆积的块通常可以组装每个单独的沸石颗粒，或者与相应的晶胞尺寸相关，约108至1010个晶胞。沸石颗粒的精细表面结构是梯田状的，相邻梯田之间的台阶通常在20 nm至60 nm的范围内;测得的最小台阶约为4 nm。通过AFM进行表面形貌的详细研究，检测块交叉处的有机分子。通过HRTEM和电子衍射观察到拓扑缺陷的存在。
High-resolution transmission (HRTEM) and high-resolution scanning electron microscopy as well as atomic force microscopy (AFM), X-ray diffraction, and electron diffraction were used for studying the zeolites MFI, MEL, and the MFI/MEL intergrowth system. All three zeolites consisted of individual particles having a size in the range of approximately 0.5 μm to 5 μm. The particle habits varied from rather cubelike to almost spherelike with many intermediate habits. Typically, the particles of these three zeolites were assembled by many individual blocks that differed in the dimension from about 25 nm to 140 nm as well as in the shape from very frequently almost rectangular (for MFI, MEL, and MFI/MEL) to sometimes roundish or irregular habits (mainly for MFI/MEL). An estimate shows that some 104 up to more than 106 densely packed blocks typically may assemble each individual zeolite particle or, related to the corresponding unit cell dimension, about 108 up to 1010 unit cells. The fine surface structure of zeolite particles was terracelike with steps between adjacent terraces typically in the range of 20 nm to 60 nm; the minimum step measured was approximately 4 nm. A detailed study of the surface topography was performed by AFM, detecting organic molecules at the block intersections. The presence of topological defects was observed by HRTEM and electron diffraction.