CO₂ Capture on Mesocellular Silica Foam Supported Amino Acid-Functionalized Ionic Liquids

Combination of active and thermally stable amino acid-functionalized ionic liquids (AAILs) with high surface area and porosity of mesocellular silica foams (MCF) to form a robust CO₂ sorbent is investigated in this study. These sorbent composites (MCF-x) are synthesized by immobilizing three AAILs (Gly, Lys, and Arg) into MCF by a simple wet-impregnation method. The prepared AAILs and MCF-x sorbents are characterized by N₂ adsorption/desorption, small-angle X-ray scattering (SAXS), elemental analysis (EA), and Fourier-transformed infrared (FTIR) spectroscopies. Their corresponding CO₂ sorption–desorption performance at 348 K under ambient pressure using dry 15 % CO₂ is also studied. The obtained results show that the AAILs have low CO₂ sorption capacities and rates because of their high viscosities. The MCF-x sorbents, however, exhibit remarkable enhancement of sorption capacities and fast kinetics. Among these sorbents, MCF-Lys possesses the superior sorption capacity of 1.38 mmol_CO2/g_sorbent, the higher tolerance to water moisture and much better long-term durability which may be a promising sorbent for CO₂ capture applications.