Textural mesoporosity and opening frame network of mesoporous MOR zeolites synthesized under intensifying perturbation conditions
Textural mesoporosity and opening frame network of mesoporous MOR zeolites synthesized under intensifying perturbation conditions
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DOI：
10.1016/j.micromeso.2011.12.038
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发表时间：
2012-05
影响因子：
5.2
通讯作者：
Yingjie Jin;Yongdan Li;Haiyan Wang;Shanlin Zhao;Z. Lv;Xiamei Du;Yueqiao Sun
中科院分区：
文献类型：
--
作者：
Yingjie Jin;Yongdan Li;Haiyan Wang;Shanlin Zhao;Z. Lv;Xiamei Du;Yueqiao Sun
通过微扰途径并使用组合模板合成了几种无定形、复合和结晶介孔硅铝酸盐。通过粉末X射线衍射、77K氮气吸附、透射电子显微镜、氨程序升温脱附和热重-差热分析，根据T1(t1)→T2(t2)的合成模式研究了强化扰动对产物相、介孔率和结构特征的影响，其中协同改变为 Ti(ti) 导致扰动强度的变化 (ΔTi(ti), i=1, 2)。因此，对合成条件施加的扰动导致所得材料的介观结构、结晶度和酸性发生显着变化。两种复合介孔材料的结构差异在于从非均匀相到次晶相的转变。具有孔隙层次的介孔丝光沸石（MOR）表现出具有大体积结构缺陷的结晶介孔结构。其中，在介观尺度上观察到的开口框架本身是结晶介孔MOR基质。这些结果证实了扰动强度作为耦合动力学因素在控制固体结晶和附加介孔性质中的重要作用。根据总可燃物和衍生焦炭的TG失重率（%）和DTA峰值温度，捕获的这些烷基铵和脂肪胺受到MOR沸石的骨架电荷和不规则介孔几何形状的强烈限制，因此部分转化为难以去除的焦炭。此外，所有介孔材料的比孔体积和总可燃失重率之间的相关性均呈现显着的线性响应。
Several amorphous, composite and crystalline mesoporous aluminosilicates were synthesized via perturbation routes and using combined templates. By powder X-ray diffraction, nitrogen adsorption at 77K, transmission electron microscopy, ammonia temperature-programmed desorption and thermogravimetric–differential thermal analyses, intensifying perturbations impacted on product phase, mesoporosity and textural feature were investigated according to synthesis modes of T1(t1)→T2(t2), wherein a cooperative alteration to Ti(ti) resulted in a variation in perturbation intensity (ΔTi(ti), i=1, 2). As a consequence, the perturbations imposed on synthesis conditions caused significant changes in mesostructure, crystallinity and acidity of resulting materials. The structural difference between two types of composite mesoporous materials was the transformation from an inhomogeneous phase into a hypocrystalline phase. Mesoporous mordenites (MOR) with a hierarchy of pores exhibited crystalline mesoporous textures featuring of bulky structural defects. Among them, opening frames per se observed in mesoscale were of crystallized mesoporous MOR matrixes. These results confirmed the important role of perturbation intensity taken as coupling kinetic factors in controlling over the solid crystalline and additional mesoporous properties. Upon TG weight loss rates (%) and DTA peak temperatures for total combustibles and derived cokes, these alkylammonium and aliphatic amines captured were strongly restricted by framework charges and irregular mesopore geometries of the MOR zeolites, and therefore partially transformed into cokes hardly to remove. Additionally, there was a prominently linear response to the correlation between specific pore volume and total combustible weight loss rate for all mesoporous materials.