Integrated\nCO<sub>2</sub> Capture and Conversion by\na Robust Cu(I)-Based Metal–Organic Framework

Metal–organic\nframeworks (MOFs) have shown promise in both\ncapturing CO<sub>2</sub> under flue gas conditions and converting\nit into valuable chemicals. However, the development of a single MOF\ncapable of capturing and selectively converting CO<sub>2</sub> has\nremained elusive due to a lack of a harmonious combination of selectivity,\nwater stability, and reactivity. For example, Cu(I)-based MOFs are\nparticularly effective for CO<sub>2</sub> conversion, but they do\nnot typically exhibit selective CO<sub>2</sub> adsorption and often\nsuffer from instability in the presence of air and moisture. Developing\na Cu(I) MOF that is stable under flue gas conditions while also capturing\nCO<sub>2</sub> from this mixture would likely afford a material capable\nof selectively capturing and converting CO<sub>2</sub> in an integrated\npathway, which would represent a significant advancement in this field.\nIn this study, we introduce <b>NU-2100</b>, an ultramicroporous\nCu(I) MOF, which exhibits both selectivity for CO<sub>2</sub> adsorption\nand great stability even in the presence of moisture and air. Comprehensive\nevaluations involving exposure to air, oxygen, water, and varying\ntemperatures reveal that <b>NU-2100</b> demonstrates superior\nstability compared to other known Cu(I) MOFs. Utilizing adsorption\nisotherms and thermogravimetric analysis coupled with gas chromatography–mass\nspectrometry (TGA-GCMS), we establish the high selectivity of <b>NU-2100</b> for CO<sub>2</sub> over common flue gas components,\nincluding water, nitrogen, and oxygen. Additionally, under mild reaction\nconditions (50 °C and H<sub>2</sub>:CO<sub>2</sub> = 3:1), <b>NU-2100</b> exhibits CO<sub>2</sub> capture and catalytic conversion\nto formic acid with 100% selectivity. This study marks an important\nstep toward the design of next-generation MOFs capable of integrated\ncarbon capture and utilization (iCCU) under industrial conditions.