Ultra-microporous MAF stu-1 modified by ammonia for efficient CO2 capture

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 CO2 capture and exhibited excellent adsorption performance and CO2/N-2 (15:85, v/v) separation efficiency. MAF stu-1-C regulated by .13 mol NH3 had small pore size of 4.9 angstrom and uncoordinated imidazole nitrogen sites in the channel, which were beneficial to improving CO2 adsorption capacity and selectivity. The maximal CO2 adsorption capacity of MAF stu-1-C was 110 cm(3)/g, exhibiting excellent CO2 capture ability and cycle stability. The ideal adsorption solution theory (IAST) model was used to calculate the adsorption and separation ratio of CO2 to N-2. The CO2 to N-2 selectivity of the modified adsorbent was more than 100. Furthermore, the adsorption heat of MAF stu-1-C for CO2 was calculated to be about 35 kJ/mol by virial equation fitting method, indicating that the modified adsorbent also had remarkable regeneration performance.