Multimodal Zr-Silicalite-1 zeolite nanocrystal aggregates with interconnected hierarchically micro-meso-macroporous architecture and enhanced mass transport property
Multimodal Zr-Silicalite-1 zeolite nanocrystal aggregates with interconnected hierarchically micro-meso-macroporous architecture and enhanced mass transport property
复制标题
多峰 Zr-Silicalite-1 沸石纳米晶聚集体，具有互连的分级微-介观-大孔结构和增强的传质性能
DOI：
10.1016/j.jcis.2012.03.018
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发表时间：
2012-07-01
影响因子：
9.9
通讯作者：
Su, Bao-Lian
中科院分区：
文献类型：
--
作者：
Chen, Li-Hua;Xu, Shu-Tao;Su, Bao-Lian
由均匀的Zr掺杂的silicalite-1沸石纳米晶构建了具有相互连接的三峰微-介-大孔体系的多级多孔结构。该合成是通过使用甘油作为反应介质，通过准固态结晶的分级介孔-大孔锆硅酸盐前体的结构导向剂TPAOH的作用下。甘油的存在是至关重要的合成系统，以保持多孔层次。采用激光-超极化核磁共振谱、紫外-可见光谱、氨程序升温脱附和催化异丙苯裂解探针反应分别研究了孔的连通性、Zr在骨架中的位置、酸性和催化活性。这些产品具有与位于大孔壁中的中孔互连的明确的大通道，而大孔壁又由微孔MFI型沸石单元构成。NMR研究表明，微孔、介孔和大孔体系在最终材料中均匀分布，相互连通，这对分子扩散具有重要作用。TPD-NH3研究表明，由Zr-Silicalite-1沸石纳米晶构建的分级微-介-大孔材料呈现强酸性。(C)2012 Elsevier Inc. All rights reserved.
Hierarchical porous architecture with interconnected trimodal micro-meso-macroporous systems constructed from uniform zeolite Zr-doped silicalite-1 nanocrystals has been prepared. The synthesis has been made by using glycerin as a reaction medium via a quasi-solid-state crystallization of hierarchically meso-macroporous zirconosilicate precursor under the effect of the structure directing agent TPAOH. The presence of glycerin is crucial in the synthesis systems to maintain the porous hierarchy. The pores inter-connectivity, Zr location in the framework, the acidity and the catalytic activity have been studied by laser-hyperpolarized Xe-129 NMR spectroscopy, UV-visible spectroscopy, temperature-programmed desorption of ammonia and the catalytic isopropylbenzene cracking probe reaction, respectively. The products possess well-defined macrochannels interconnected with mesopores located in the macropore walls, which in turn have been constructed from microporous MFI-type zeolite units. Xe-129 NMR study indicated that the hierarchically micro-, meso-, macro-pore systems are homogeneously distributed throughout the final materials and well interconnected, which is important for molecular diffusion. The TPD-NH3 investigation revealed that the hierarchically micro-meso-macroporous materials constructed from zeolite Zr-Silicalite-1 nanocrystals present strong acidity. (C) 2012 Elsevier Inc. All rights reserved.