Aminopropyl-functionalized mesoporous silicas as CO2 adsorbents

A range of mesoporous silica substrates were functionalized with 3-aminopropyltrimethoxysilane to form hybrid products suitable for carbon dioxide adsorption. A ‘cylindrical pore’ model was employed to characterize the extent of surface modification per unit substrate surface area and to permit its comparison on a common basis. The extent of surface functionalisation varied with substrate morphology. Combined DTA/TGA was used to characterise CO2 adsorption. Substantial reversible CO2 adsorption capacities were observed under anhydrous conditions (at 20 °C). In the presence of water, CO2 capacity was enhanced, but the rate of desorption was diminished.