Bimetallic UTSA-16 (Zn, X; X = Mg, Mn, Cu) metal organic framework developed by a microwave method with improved CO2capture performances

A series of bimetallic UTSA-16 (Zn, X; X = Mg, Mn, and Cu) metal organic frameworks (MOFs) with different metal ratios was synthesized using a microwave irradiation method. Synthesis at an optimal Zn-to-metal ratio of 7:2 achieved a 9–18% increase in the CO2 adsorption capacity and an enhanced adsorption selectivity of CO2 over N2 compared to those of the parent UTSA-16 (Zn). Bimetallic UTSA-16 powders, with ratios of 7:2, were pelletized for a stability study that exposed the pellets to acid gases (NO2 and SO2) in a humid air condition; additionally, they underwent adsorption–desorption cyclic experiments. The results showed that the CO2 capture performance was consistent after exposure to NO2 gas in humid air and adsorption–desorption cycling with temperature swing. The morphological properties of the bimetallic MOFs were characterized using scanning electron microscopy, Brunauer − Emmett − Teller analysis, Fourier transform infrared spectroscopy, and X-ray diffraction. The characterization data showed that the bimetallic UTSA-16 (Zn, X) MOFs exhibited good crystallinity and morphology, similar to the original UTSA-16 (Zn) MOF.