Amino-Functionalizing Ce-Based MOF UiO-66 for Enhanced CO₂ Adsorption and Selectivity

Metal-organic frameworks (MOF) hold great promise for CO₂ adsorption due to their high surface areas, tunable pore sizes, and the ability to modify their chemical properties to enhance CO₂ affinity. MOFs tagged with functional groups either at linker or metal sites have shown improved CO₂ uptake capacity and selectivity. This study focuses on investigating the potential of selective CO₂ adsorption using amino functionalization of linker forming Ce-UiO-66. The physicochemical properties and characteristics of MOFs to determine the degree of amino functionalization and structural stability were examined using powder X-ray diffraction (PXRD), Fourier transformer infra-red (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and N₂ porosimetry and specific surface area (BET). This work unveils a novel array of results on CO₂, N₂ and water vapour adsorption on Ce-UiO-66-NH₂. The amino-functionalized Ce-UiO-66-NH₂ shows 63 % higher CO₂ uptake and 84 % higher CO₂/N₂ selectivity at 273 K and 1 bar over Ce-UiO-66. Ce-UiO-66-NH₂ also shows excellent structural stability after gas and vapour sorption making Ce-UiO-66-NH₂ potential adsorbent for CO₂ capture.