Metal-organic framework MIL-101 loaded with polymethacrylamide with or without further reduction: Effective and selective CO2 adsorption with amino or amide functionality

In order to improve the performances of a typical/highly porous metal-organic framework (MOF, MIL-101 structure) in CO2 adsorption/capture, methacrylamide was polymerized (to polymethacrylamide or PM) inside of MIL-101 (to get PM@MOF) and further reduced with lithium aluminum hydride. The obtained adsorbents (R-PM24@MOF or PM24@MOF) had highly enhanced performances, compared with the pristine MOF, in CO2 capture both in the adsorption capacity (especially at low pressure of 0.15 atm) and adsorption selectivity (against N-2), suggesting the polyamides loading (and subsequent reduction) on MOFs is an effective mean to derive competitive adsorbent for CO 2 adsorption/capture. For example, the developed adsorbent (R-PM24@ MOF) showed 1.4 mmol/g of adsorbed CO2 (at 0.15 atm and 298 K) and adsorption selectivity (CO2/N-2) of 143 at 298 K (CO2/N-2 = 0.75/0.15, at 1 atm); which are similar to 3 and similar to 10 times to that of pristine MIL-101, respectively. The remarkably enhanced performances could be explained with the introduced functional groups and reduced porosity (for decreased N-2 adsorption). Moreover, the adsorbent could be easily recycled, suggesting the potential application in selective adsorption of CO2 from off gas of post-combustions.