02138nas a2200241   4500008004100000022001400041245009000055210006900145260007300214300001200287490000700299520131000306653001801616653002201634653001201656653001601668653001601684653002101700100001901721700001701740700001801757856012101775       2006                        eng d  a1566-736700aSites for CO2 activation over amine-functionalized mesoporous Ti(Al)-SBA-15 catalysts0 aSites for CO2 activation over aminefunctionalized mesoporous TiA  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAR  a314-3260 v903 a<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 (''</p>10aaromatization10aGa-based zeolites10apropane10aSi/Al ratio10aSi/Ga ratio10azeolitic factors1 aSrivastava, R.1 aSrinivas, D.1 aRatnasamy, P.  uhttps://library.ncl.res.in/content/sites-co2-activation-over-amine-functionalized-mesoporous-tial-sba-15-catalysts-1