One-step synthesis of hydrothermally stable mesoporous aluminosilicates with strong acidity
Author(s)
Yang, Dongjiang
Xu, Yao
Wu, Dong
Sun, Yuhan
Griffith University Author(s)
Year published
2008
Metadata
Show full item recordAbstract
ing tetraethylorthosilicate (TEOS), polymethylhydrosiloxane (PMHS) and aluminium isopropoxide (AIP) as the reactants, through a one-step nonsurfactant route based on PMHS-TEOS-AIP co-polycondensation, hydrothermally stable mesoporous aluminosilicates with different Si/Al molar ratios were successfully prepared. All samples exclusively showed narrow pore size distribution centered at 3.6 nm. To assess the hydrothermal stability, samples were subjected to 100 àdistilled water for 300 h. The boiled mesoporous aluminosilicates have nearly the same N2 adsorption-desorption isotherms and the same pore size distributions as those ...
View more >ing tetraethylorthosilicate (TEOS), polymethylhydrosiloxane (PMHS) and aluminium isopropoxide (AIP) as the reactants, through a one-step nonsurfactant route based on PMHS-TEOS-AIP co-polycondensation, hydrothermally stable mesoporous aluminosilicates with different Si/Al molar ratios were successfully prepared. All samples exclusively showed narrow pore size distribution centered at 3.6 nm. To assess the hydrothermal stability, samples were subjected to 100 àdistilled water for 300 h. The boiled mesoporous aluminosilicates have nearly the same N2 adsorption-desorption isotherms and the same pore size distributions as those newly synthesized ones, indicating excellent hydrothermal stability. The 29Si MAS NMR spectra confirmed that PMHS and TEOS have jointly condensed and CH3 groups have been introduced into the materials. The 27Al MAS NMR spectra indicated that Al atoms have been incorporated in the mesopore frameworks. The NH3 temperature-programmed desorption showed strong acidity. Due to the existence of large amount of CH3 groups, the mesoporous aluminosilicates obtained good hydrophobicity. Owing to the relatively large pore and the strong acidity provided by the uniform four-coordinated Al atoms, the excellent catalytic performance for 1,3,5-triisopropylbenzene cracking was acquired easily. The materials may be a profitable complement for the synthesis of solid acid catalysts.
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View more >ing tetraethylorthosilicate (TEOS), polymethylhydrosiloxane (PMHS) and aluminium isopropoxide (AIP) as the reactants, through a one-step nonsurfactant route based on PMHS-TEOS-AIP co-polycondensation, hydrothermally stable mesoporous aluminosilicates with different Si/Al molar ratios were successfully prepared. All samples exclusively showed narrow pore size distribution centered at 3.6 nm. To assess the hydrothermal stability, samples were subjected to 100 àdistilled water for 300 h. The boiled mesoporous aluminosilicates have nearly the same N2 adsorption-desorption isotherms and the same pore size distributions as those newly synthesized ones, indicating excellent hydrothermal stability. The 29Si MAS NMR spectra confirmed that PMHS and TEOS have jointly condensed and CH3 groups have been introduced into the materials. The 27Al MAS NMR spectra indicated that Al atoms have been incorporated in the mesopore frameworks. The NH3 temperature-programmed desorption showed strong acidity. Due to the existence of large amount of CH3 groups, the mesoporous aluminosilicates obtained good hydrophobicity. Owing to the relatively large pore and the strong acidity provided by the uniform four-coordinated Al atoms, the excellent catalytic performance for 1,3,5-triisopropylbenzene cracking was acquired easily. The materials may be a profitable complement for the synthesis of solid acid catalysts.
View less >
Journal Title
Journal of Solid State Chemistry
Volume
181
Issue
9
Subject
Macromolecular and Materials Chemistry not elsewhere classified
Inorganic Chemistry
Macromolecular and Materials Chemistry
Physical Chemistry (incl. Structural)