Efficient CO2 Capture under Humid Conditions on a Novel Amide-Functionalized Fe-soc Metal–Organic Framework

CO2 is the main source of the greenhouse gases, and its capture from flue gas under humid conditions is challenging but important for promoting carbon neutrality. Herein, we report a novel soc topology Fe-based metal-organic framework (Fe-dbai) with highly efficient postcombusion CO2 capture performance by integrating multiple specific functionalities, such as unsaturated metal sites and amide functional groups. The CO2 adsorption capacity and CO2/N2 selectivity of Fe-dbai are high up to 6.4 mmol/g and 64 (298 K, 1 bar), respectively, superior to many other reported MOFs. More importantly, the CO2 working capacity of Fe-dbai under 60% RH conditions preserves 94% of that under dry conditions in the breakthrough experiments of CO2/N2 (15:85, v/v) mixtures. The molecular simulation highlights that the electronegative amide CO- group has a good affinity for CO2 and can improve the interaction between Fe UMS and CO2. Although H2O molecules will occupy a small fraction of the adsorption sites, the confinement effect it produces can enhance the adsorption affinity of the framework for CO2, which results in Fe-dbai retaining most of the CO2 adsorption capacity under humid conditions. The excellent CO2 capture performance makes Fe-dbai a potential candidate for the practical application of CO2 capture.