Polyethyleneimine-Modified UiO-66-NH2(Zr) Metal–Organic Frameworks: Preparation and Enhanced CO2 Selective Adsorption

• DOI: 10.1021/acsomega.8b02319
• Publication Date: 2019-02-13T21:17:17Z
• Authors: Junjie Zhu; Linbo Wu; Zhiyang Bu; Suyun Jie; Bo-Geng Li
• Keywords: Thermogravimetric analysis; Glutaraldehyde; Specific surface area

UiO-66-NH2, a zirconium-based functional metal–organic framework (MOF), was postsynthetically modified via Schiff base reaction between aldehyde groups in glutaraldehyde and amino UiO-66-NH2 CO2-preabsorbed polyethyleneimine (PEI). The resulting PEI-modified MOFs, abbreviated as PEIC@UiO, were characterized with 1H NMR, Fourier transform infrared, powder X-ray diffraction, Brunauer–Emmett–Teller, scanning electron microscopy, thermogravimetric analysis evaluated CO2 adsorbents. In comparison pristine the PEIC@UiO adsorbents have reduced specific surface area (7–150 m2/g) but maintained same crystal structure. Particularly, PEIC96@UiO adsorbent exhibited significantly improved CO2/N2 adsorption selectivity (48 vs 25) higher capacity (3.2 2.7 mmol/g). also displayed moderate desorption energy (68 kJ/mol CO2), superior moisture endurance, recyclability, which are very desirable for practical applications.