Novel amine-functionalized Mg-MOF CO2 adsorbents with bi-functional adsorption-screening

Metal-organic frameworks (MOFs) are promising materials for the efficient capture of CO2. Nevertheless, the weak interaction between the MOFs and CO2 molecules impede the equilibrium between the adsorption capacity and selectivity of CO2. Furthermore, the lower CO2 adsorption performance, lower selectivity, and lower synthesis yield of MOFs than those of other adsorbents and their inhomogeneity are major drawbacks. Herein, to improve the conventional Mg-based MOFs adsorbents, pore length of the Mg-MOF materials was shortened, while obtaining a more dispersible particle structure. By utilizing the macromolecular amine structure, amine molecules were vapor-deposited into the MOF pores. The CO2 adsorption capacity was demonstrated to be as high as 203 mL g-1 (273 K, 1 bar), and the IAST adsorption selectivity was as high as 304. GCMC and DFT simulations showed that the sequential construction of short-dispersed pores and the introduction of pore-matching amine structures improved the adsorption performance and selectivity of CO2. This work offers insights into for the design and controllable preparation principles of the adsorption and screening of bi-functional Mg-based MOFs-based carbon capture materials and provides a fundamental basis for obtaining MOF-based carbon capture materials with improved efficiency.