Sites for CO2 activation over amine-functionalized mesoporous Ti(Al)-SBA-15 catalysts

TitleSites for CO2 activation over amine-functionalized mesoporous Ti(Al)-SBA-15 catalysts
Publication TypeJournal Article
Year of Publication2006
AuthorsSrivastava, R, Srinivas, D, Ratnasamy, P
JournalMicroporous and Mesoporous Materials
Volume90
Issue1-3
Pagination314-326
Date PublishedMAR
Type of ArticleArticle
ISSN1566-7367
Keywordsaromatization, Ga-based zeolites, propane, Si/Al ratio, Si/Ga ratio, zeolitic factors
Abstract

{Activation of CO and its utilization in the synthesis of chloropropene and styrene carbonates over functionalized, mesoporous SBA-15 solids, have been investigated. The surface basicity of SBA-15 was modified with nitrogen-based organic molecules of varying basicity viz., alkyl amines (-NH2), adenine (Ade), imidazole (Im) and guanine (Gua). The surface of SBA-15 was also functionalized with Ti4+ and Al3+ species. The acid-base properties of these modified SBA-15 materials were investigated by temperature-programmed desorption (TPD) and diffuse-reflectance infrared Fourier transform (DRIFT) spectroscopy. NH3 and pyridine were used as probe molecules for acid sites, while CO, was used to characterize the basic sites. CO was activated at the basic amine sites forming surface carbamate species (IR peaks: 1609 and 1446 cm(-1)). The latter reacted further with epoxides adsorbed on the acid sites forming cyclic carbonates. A correlation between the intensity of the IR peak at 1609 cm(-1) and cyclic carbonate yield has been observed. The cyclic carbonate yields were higher when both the acid and base functionalities were present on the surface. The Ti- and Al-SBA-15 functionalized with adenine exhibited the highest catalytic activity and selectivity. There is an optimal dependence (''

DOI10.1016/j.micromeso.2005.10.043
Type of Journal (Indian or Foreign)

Foreign

Impact Factor (IF)3.349
Divison category: 
Catalysis and Inorganic Chemistry