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Phenyl-modified Sba-15 And Directly Synthesis And Application Of Exploration And Research

Posted on:2005-12-15Degree:MasterType:Thesis
Country:ChinaCandidate:Y L HuangFull Text:PDF
GTID:2191360125469475Subject:Organic Chemistry
Abstract/Summary:PDF Full Text Request
Organic` group modified mesoporous molecular sieves have attracted much attention in recent years. Surface modification can considerably enhance the versatility of mesoporous silica providing more potential applications and a number of organic groups have been covalently attached. Due to its easy synthesis, adjustable pore size, thick pore wall and remarkable hydrothermal stability, we chose SBA-15 as matrix. Zeolites have been tested as potential suitable organic acid or inorganic acid materials, owing to their well-known acid strength and size limitation imposed to the reaction products by the pore dimension. But SBA-15 itself has no acidity. we could get it by introducing acid group. We have aimed to prepare high acid mesoporous molecular sieves.The phenyl-functionalized-SBA-15 (Ph-SBA-15) mesoporous molecular sieve was synthesized by means of a simple one-step synthesis approach involving co-condensation of tetraethoxysilane (TEOS) and phenyltriethoxysilane (PTES) in the presence of a poly(alkylene oxide) block copolymer (Pluronic 123) under acidic condition. When the sample was calcined at 300℃ for 6 hours, the phenyl groups were still stable and the template P123 was completely removed.We successfully synthesized highly phenyl-functionalized cubic mesoporous silica (FUD-5) with Ia3d symmetry under conventional hydrothermal condition and no organic additive, which is stable to surfactant removal by solvent extraction and controlled calcination.Sulfonic groups were successfully introduced into the Ph-SBA-15 materials. The HSO3-Ph-SBA-15 featured well-ordered hexagonal arrays of mesopores and the pore channels were similar to those in the pure SBA-15. The acidity test of the sulfonated materials showed that the acidity content was 4.19mmol/g and the esterification test also presented that it owned catalytic activity.Pore size engineering is an increasingly interesting issue in the development of mesoporous molecular sieves. We use pore swelling agent as auxiliary organics to expand the pore size of Ph-SBA-15.
Keywords/Search Tags:Mesoporous molecular sieve, SBA-15, modification, Sulfonation, Pore size design
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