Two calcined mesoporous supports, silica and titania, were functionalized with aminopropylsilane (APS). The samples were characterized using ATR (attenuated total reflectance), nitrogen sorption at 77 K, and thermogravimetric analysis. The functionalized silica and titania are mesoporous and were grafted with 1.4 and 1.6 molecules of APS per nm 2 , respectively. Infrared measurements propose that the properties of the amine sites are affected by the chemical properties of the support. For example, the NH 2 bending vibration δ(NH) was shifted to lower wavenumbers from 1597 to 1575 cm -1 from the silica to the titania grafted sample, respectively. This could be explained by different interactions with the surface hydroxyl groups of silica and titania. The grafted samples were investigated for carbon dioxide adsorption by combining microcalorimetry and in situ FTIR spectroscopy. Their CO 2 adsorption properties are presented in comparison to the nongrafted support materials. Microcalorimetric measurements show important enthalpies of adsorption at low CO 2 coverage (more than -80 kJ mol -1 ) for the APS-grafted materials, indicating a strong reactivity between carbon dioxide and the amine sites. In situ infrared spectroscopy was used to study this reactivity. The formation of three products (carbamate, carbamic acid, and bidentate carbonate) is proposed.

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Silver nanoparticles have been produced by γ-irradiation of silver solution in optically transparent inorganic mesoporous silica. The reduction of Ag + within the matrix is brought about by hydrated electrons and hydroalkyl radicals generated during the radiolysis of the 2-propanol solution. The particles formed within the silica matrix were studied by electron microscopy, nitrogen sorption measurements, and absorption spectroscopy. The particles were mostly confined and dispersed in the pores of the mesoporous hosts. Absorption spectra show that the mean Ag clusters size increases with the irradiation dose. At high dose, agglomerated large particles are formed. In contrast, at a given dose, the effect of the dose rate has been clearly demonstrated to lower the cluster size. The silver particles within the silica matrix are stable in the presence of oxygen for at least several months.