@article {36},
	title = {Sites for CO2 activation over amine-functionalized mesoporous Ti(Al)-SBA-15 catalysts},
	journal = {Microporous and Mesoporous Materials},
	volume = {90},
	number = {1-3},
	year = {2006},
	month = {MAR},
	pages = {314-326},
	publisher = {ELSEVIER SCIENCE BV},
	type = {Article},
	address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS},
	abstract = {<p>{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 ({\textquoteright}{\textquoteright}</p>},
	keywords = {aromatization, Ga-based zeolites, propane, Si/Al ratio, Si/Ga ratio, zeolitic factors},
	issn = {1566-7367},
	doi = { 10.1016/j.micromeso.2005.10.043},
	author = {Srivastava, R. and Srinivas, D. and Ratnasamy, P.}
}
@article { ISI:000238111400026,
	title = {Syntheses of polycarbonate and polyurethane precursors utilizing CO2 over highly efficient, solid as-synthesized MCM-41 catalyst},
	journal = {Tetrahedron Letters},
	volume = {47},
	number = {25},
	year = {2006},
	month = {JUN},
	pages = {4213-4217},
	publisher = {PERGAMON-ELSEVIER SCIENCE LTD},
	type = {Article},
	address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND},
	abstract = {<p>As-synthesized MCM-41 was used as a reusable, heterogeneous catalyst for the eco-friendly synthesis of cyclic carbonate precursors of polycarbonates via a cycloaddition reaction of CO2 with epoxides. This catalyst is also efficient for the synthesis of alkyl and aryl carbamate precursors of polyurethanes via the reaction of amines, CO2 and alkyl halides. Both these reactions were carried out under mild conditions and without using any solvent or co-catalyst. CO2 is utilized as a raw material replacement for toxic phosgene in the conventional synthesis of these chemicals. (c) 2006 Elsevier Ltd. All rights reserved.</p>},
	keywords = {carbamates, carbon dioxide utilization, CO2 fixation, cyclic carbonates, eco-friendly processes, MCM-41, polycarbonates, polyurethanes},
	issn = {0040-4039},
	doi = {10.1016/j.tetlet.2006.04.057},
	author = {Srivastava, R. and Srinivas, D. and Ratnasamy, P.}
}
