UiO-66-NH2(Zr), a zirconium-based functional metal–organic framework (MOF), was post synthetically modified via Schiff base reaction between aldehyde groups in glutaraldehyde and amino groups in UiO-66-NH2 and CO2-preabsorbed polyethyleneimine (PEI). Compared with pristine UiO-66-NH2, the PEIC@UiO adsorbents have reduced specific surface area (7–150 m2/g) but maintained the same crystal structure. Notably, the PEIC96@UiO adsorbent exhibited significantly improved CO2/N2 adsorption selectivity (48 vs 25) and higher CO2 adsorption capacity. The adsorbent also displayed moderate desorption energy (68 kJ/mol CO2), superior moisture endurance, and recyclability[1].
