Silica sources influence different aspects of Al-MCM-41 product. The crystallinity of nanosized Al-MCM-41 zeolites prepared crystallization and lead to change in the properties of the final from precursors mixtures co...Silica sources influence different aspects of Al-MCM-41 product. The crystallinity of nanosized Al-MCM-41 zeolites prepared crystallization and lead to change in the properties of the final from precursors mixtures containing different silica sources, e.g. tetraethylorthosilicate （TEOS）, colloidal silica （CS）, silicic acid （SA） and fumed silica （FS） have been studied. The produced samples are investigated using XRD, SEM, FT-IR, pyridine adsorption and N2 physisorption. XRD results show that the products obtained from different silica sources are in Al-MCM-41 phase. SEM results show that silica sources influence the produced Al-MCM-41 shape. Using silicic acid leads to formation of spherical crystals, TEOS gives cubical crystals, colloidal silica forms spherical crystals with smaller aggregated, and fumed silica gives rounded crystals. N2 physisorption results show that silica sources influence pore-diameter and pore-volume of the produced Al-MCM-41 ; the pore diameter of the produced Al-MCM-41 in case of colloidal silica, TEOS, fumed silica, and silicic acid are 12, 20, 15, and 17A respectively. Also, the pore volume of the produced AI-MCM-41 in case of colloidal silica, TEOS, fumed silica and silicic acid are 0.78, 0.71, 0.76, and 0.8 cm^3/gm, respectively.展开更多
文摘Silica sources influence different aspects of Al-MCM-41 product. The crystallinity of nanosized Al-MCM-41 zeolites prepared crystallization and lead to change in the properties of the final from precursors mixtures containing different silica sources, e.g. tetraethylorthosilicate （TEOS）, colloidal silica （CS）, silicic acid （SA） and fumed silica （FS） have been studied. The produced samples are investigated using XRD, SEM, FT-IR, pyridine adsorption and N2 physisorption. XRD results show that the products obtained from different silica sources are in Al-MCM-41 phase. SEM results show that silica sources influence the produced Al-MCM-41 shape. Using silicic acid leads to formation of spherical crystals, TEOS gives cubical crystals, colloidal silica forms spherical crystals with smaller aggregated, and fumed silica gives rounded crystals. N2 physisorption results show that silica sources influence pore-diameter and pore-volume of the produced Al-MCM-41 ; the pore diameter of the produced Al-MCM-41 in case of colloidal silica, TEOS, fumed silica, and silicic acid are 12, 20, 15, and 17A respectively. Also, the pore volume of the produced AI-MCM-41 in case of colloidal silica, TEOS, fumed silica and silicic acid are 0.78, 0.71, 0.76, and 0.8 cm^3/gm, respectively.
