CO₂ capture & separation in microporous materials: A comparison between porous carbon and flexible MOFs

The stereotype of flexible MOFs(Amino-MIL-53) and carbonized porous carbon prepared from renewable resources is successfully synthesized for CO₂ reduction application. The textural properties of these microporous materials are investigated, and their CO₂ storage capacity and separation performance are evaluated. Owing to the combined effects of CO₂-Amino interaction and its flexibility, a CO₂ uptake of 2.5 mmol g^-1 is observed in Amino-MIL-53 at 20 bar 298 K. In contrast, CH₄ uptake in Amino-MIL-53 is very low up to 20 bar, implying potential sorbent for CO₂/CH₄ separation. Carbonized samples contain a small quantity of metal residues(K, Ca, Mg, S), resulting in naturally doped porous carbon. Due to the trace metal, even higher CO₂ uptake of 4.7 mmol g^-1 is also observed at 20 bar 298 K. Furthermore, the CH₄ storage capacity is 2.9 mmol g^-1 at 298 K and 20 bar. To evaluate the CO₂ separation performance, the selectivity based on ideal adsorption solution theory for CO₂/CH₄ binary mixtures on the presented porous materials is investigated.