Please use this identifier to cite or link to this item:
|Title:||Effect of tin precursors and crystallization temperatures on the synthesis of SBA-15 with high levels of tetrahedral tin|
|Source:||Selvaraj, M., Kawi, S. (2007). Effect of tin precursors and crystallization temperatures on the synthesis of SBA-15 with high levels of tetrahedral tin. Journal of Materials Chemistry 17 (34) : 3610-3621. ScholarBank@NUS Repository. https://doi.org/10.1039/b706647c|
|Abstract:||Mesoporous SnSBA-15 materials with different tin precursors, crystallization temperatures, and nSi/nSn ratio = 5, 10, 15, 30, 60 and 100, have been synthesized using Pluronic 123 triblock polymer [(EO)20(PO)70(EO)20] as a structure-directing agent by simply adjusting the molar ratio of water to hydrochloric acid (n H2O/nHCl). The effect of the nature of the tin-ion precursor on the synthesis of SnSBA-15 has been investigated using different tin-ion precursors, viz., tin(iv) chloride pentahydrate and tin(iv) acetate. To investigate the effects on the structural and textural properties of the incorporation of tin ions, SnSBA-15 was then synthesized with different crystallization temperatures at fixed molar ratios of nSi/n Sn = 10 and nH2O/nHCl = 295 in the synthesis gel. The hydrothermal stability of SnSBA-15 was also investigated. The calcined SnSBA-15 materials were characterized by ICP-AES, XRD, N2 adsorption, UV-vis DRS, 29Si MAS-NMR, FE-SEM and TEM. The ICP-AES results show a higher amount of tin-ion incorporation on the silica pore walls, as SnSBA-15 with nSi/nSn ratio up to 13.5 can be successfully prepared at a fixed nH2O/nHCl molar ratio of 295 by adjusting the ratio of nSi/nSn in the synthesis gel. The structural and textural properties of calcined SnSBA-15 can be found from the results of XRD, and N2 adsorption. The UV-vis DRS and 29Si MAS-NMR results illustrate the effects of structure and tin-ion coordination on the SBA-15 silica pore walls while the uniform pore diameter and rope-like hexagonal mesoporous structure of SnSBA-15 can be identified from the TEM and FE-SEM images. With increasing crystallization temperature, increases of the unit cell parameter, pore size and pore volume, and decreases of the specific surface area and pore wall thickness of SnSBA-15 can be found from the results of XRD and N2 adsorption. Finally, hexagonal SnSBA-15(5) is more hydrothermally stable than SnSBA-15(100), from the results of XRD, N2 adsorption, and FE-SEM. © The Royal Society of Chemistry.|
|Source Title:||Journal of Materials Chemistry|
|Appears in Collections:||Staff Publications|
Show full item record
Files in This Item:
There are no files associated with this item.
checked on Mar 7, 2018
WEB OF SCIENCETM
checked on Nov 16, 2017
checked on Mar 9, 2018
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.