One-pot synthesis of hierarchical porous layered hybrid materials based on aluminosilicate sheets and organic functional pillars
作者:Aidé Gaona、José María Moreno、Alexandra Velty、Urbano Díaz、Avelino Corma
DOI:10.1039/c4ta04742g
日期:——
Layered hybrid materials (LHMs) based on ordered silicoaluminate sheets linked with organic fragments, perpendicularly located and stabilized in the interlayer space, were synthesized by a one-pot direct hydrothermal process in the absence of structural directing agents (SDAs) and using bridged silsesquioxanes as organosilicon precursors. By following the synthesis described here, the preliminary preparation of inorganic layered precursors, post-synthesis swelling and/or pillaring treatments can be avoided. The physico-chemical and structural characteristics of the materials were studied by chemical and thermogravimetrical analyses, X-ray diffraction, TEM microscopy, spectroscopic techniques (NMR and FTIR) and textural measurements. The complete exchange of intracrystalline sodium cations by protons, without substantial structural alteration of the hybrid materials, facilitated the generation of hybrid materials, which contained acid and base sites located in the inorganic (silicoaluminate layers) and in the organic interlayer linkers, respectively, with the resultant acid–base materials showing promise as active and selective catalysts.
在没有结构引导剂(SDA)的情况下,使用桥接硅喹喔烷作为有机硅前驱体,通过单锅直接水热法合成了基于有序硅铝酸盐片与有机片段连接的层状杂化材料(LHMs),这些有机片段垂直分布并稳定在层间空间。按照本文所述的合成方法,可以避免无机层状前驱体的初步制备、合成后的膨胀和/或起球处理。通过化学和热重分析、X 射线衍射、TEM 显微镜、光谱技术(核磁共振和傅立叶变换红外光谱)和纹理测量,对材料的物理化学和结构特性进行了研究。质子完全交换了晶体内的钠阳离子,而杂化材料的结构没有发生实质性改变,这促进了杂化材料的产生,杂化材料中的酸和碱位点分别位于无机层(硅铝酸盐层)和有机层间连接体中,由此产生的酸碱材料有望成为具有活性和选择性的催化剂。