由纳米晶前驱体组装有序介孔silicalite-1分子筛

采用两步法将不同尺寸的silicalite-1分子筛纳米晶种通过自组装合成了一系列有序介孔silicalite-1分子筛。首先将强碱性的silicalite-1前驱体分别加热不同时间得到纳米晶种，然后在类似合成SBA-15的强酸性条件下组装成有序的介孔材料。合成条件的剧烈变化阻止了分子筛晶种的继续长大，并在三嵌段共聚物模板的诱导下组装成有序介孔材料。这种“自下而上”的方法制备有序介孔分子筛同时包含微孔和介孔。氮气吸脱附结果表明所制备的介孔分子筛材料均表现了很大的比表面积(730 m2/g以上)。

Ordered mesoporous silcalite-1 zeolite assembled from colloidal nanocrystalline precursors

A series of ordered mesoporous silicalite-1 zeolites has been synthesized by the self-assembly of nanosized zeolite silicalite-1 seeds with different sizes using a two-step procedure. The nanosized silicalite-1 seeds were prepared with an alkali precursor solution that was heated for different pe-riods, and then assembled into ordered mesoporous materials under strongly acidic conditions, similar to that of mesoporous silica SBA-15 which has well ordered hexagonal mesopores and amorphous walls. A significant change in synthesis conditions prevents the continued growth of zeolite seeds and induces assemblage into ordered mesoporous materials templated by triblock copolymers. The samples assembled by zeolite nanoclusters were investigated by X-ray diffraction, electron microscopy, infrared spectroscopy, and N2 adsorption-desorption isotherms. This “bot-tom-up”approach yields porous materials that contain ordered micro-and mesopores. The meso-porous zeolite has a large surface area (>730 m2/g).