Ultra‐microporous MAF stu‐1 modified by ammonia for efficient CO 2 capture

Abstract A series of ultra‐microporous rod‐shaped three‐dimensional metal organic frameworks MAF stu‐1 modified with different amounts of ammonia water were synthesized by solvothermal method using chelated nitrogen‐containing ligands, which was applied to CO 2 capture and exhibited excellent adsorption performance and CO 2 /N 2 (15:85, v/v) separation efficiency. MAF stu‐1‐C regulated by .13 mol NH 3 had small pore size of 4.9 Å and uncoordinated imidazole nitrogen sites in the channel, which were beneficial to improving CO 2 adsorption capacity and selectivity. The maximal CO 2 adsorption capacity of MAF stu‐1‐C was 110 cm 3 /g, exhibiting excellent CO 2 capture ability and cycle stability. The ideal adsorption solution theory (IAST) model was used to calculate the adsorption and separation ratio of CO 2 to N 2 . The CO 2 to N 2 selectivity of the modified adsorbent was more than 100. Furthermore, the adsorption heat of MAF stu‐1‐C for CO 2 was calculated to be about 35 kJ/mol by virial equation fitting method, indicating that the modified adsorbent also had remarkable regeneration performance.