DMOF-1 as a Representative MOF for SO2 Adsorption in Both Humid and Dry Conditions

The mixed-ligand metal–organic framework (MOF) DMOF-1 has been successfully synthesized via ligand: 2,3,5,6-tetramethylterephthalic acid (TM), 9,10-anthracenedicarboxylic acid (ADC), 1,4-naphthalenedicarboxylic acid (NDC), 2,5-dimethyl terephthalic acid (DM), and metal (Zn, Cu, Ni, Co) substitutions to develop structure–property relationships for adsorption of water and SO2, an acid gas commonly found in flue gas streams at ppm-level concentrations. The substitution of bulky ligands, TM and ADC, resulted in not only improved water stability but also stability toward dry SO2, whereas substitution with NDC and DM did not provide water or SO2 stability. ADC-functionalized Zn–DMOF exhibited the greatest stability under humid SO2 exposure of the ligand-functionalized materials that were tested. Metal substitution of Cu into the DMOF–TM structure resulted in the greatest stability of the M–DMOF–TM samples upon exposure to humid SO2, and Ni–DMOF–TM provided the second most stable material. These results follow t...