Hollow silicalite-1 zeolite can be readily fabricated by hydrothermally treating the parent silicalite-1 with tetrapropylammonium hydroxide. A dissolution-recrystallization mechanism has been previously proposed to ex...Hollow silicalite-1 zeolite can be readily fabricated by hydrothermally treating the parent silicalite-1 with tetrapropylammonium hydroxide. A dissolution-recrystallization mechanism has been previously proposed to explain the formation of such hollow structures, but detailed information of this formation process still remains unclear. Herein, by tracking the evolvement of the hollow voids and morphology of the silicalite-1 under various treatments using XRD, SEM, TEM and N2 adsorption/desorption techniques, we systematically studied the formation process of the hollow structure of silicalite-1 zeolite and discovered that the organic template, water, treating temperature and time can significantly influence the morphology and size of hollow structure inside silicalite-1 zeolite crystals. Generally, a diluted synthesis medium with high template content under suitable temperature(for instance 170 °C) and extended treatment time favors the formation of single hexagonal hollow structure within silicalite-1 zeolites;while other conditions favor the formation of rounded hollow voids or even multiple-voids within silicalite-1 zeolites.展开更多
基金supported by the Scientific Research Fund Project of National Natural Science Foundation of China(21835002)the Young Elite Scientist Sponsorship Program by CAST(2017QNRC001)partially supported by ChEM,SPST,ShanghaiTech(Grant 02161943)
文摘Hollow silicalite-1 zeolite can be readily fabricated by hydrothermally treating the parent silicalite-1 with tetrapropylammonium hydroxide. A dissolution-recrystallization mechanism has been previously proposed to explain the formation of such hollow structures, but detailed information of this formation process still remains unclear. Herein, by tracking the evolvement of the hollow voids and morphology of the silicalite-1 under various treatments using XRD, SEM, TEM and N2 adsorption/desorption techniques, we systematically studied the formation process of the hollow structure of silicalite-1 zeolite and discovered that the organic template, water, treating temperature and time can significantly influence the morphology and size of hollow structure inside silicalite-1 zeolite crystals. Generally, a diluted synthesis medium with high template content under suitable temperature(for instance 170 °C) and extended treatment time favors the formation of single hexagonal hollow structure within silicalite-1 zeolites;while other conditions favor the formation of rounded hollow voids or even multiple-voids within silicalite-1 zeolites.
