Tetraethylenepentamine-modified mesoporous adsorbents for CO2 capture: effects of preparation methods

Tetraethylenepentamine (TEPA)-modified mesocellular silica foams (MSFs) were fabricated via physical impregnation (MSF-T-x) and chemical grafting (MSF-CT-y) methods. The CO2 adsorption on these TEPA-modified MSFs was measured by using microbalances at 348 K and their adsorption capacities were observed to be 26.4-193.6 mg CO2/g-sorbent under ambient pressure using dry 15 % CO2. It was found that the CO2 adsorption capacities of MSF-CT-y were smaller than those of MSF-T-x sorbents which may be attributed to their higher density of amine groups. On the contrary, MSF-CT-y exhibited enhanced stability during repeated adsorption-desorption cycles compared to MSF-T-x sorbents. This notable enhancement in the durability of CO2 adsorption-desorption process was probably attributed to the decreased leaching of TEPA which is chemically bonded to the surface of MSF.