Effects of functional groups for CO2 capture using metal organic frameworks

Abstract

Metal organic frameworks (MOFs) are promising adsorbents for CO2 capture. Functional groups on organic linkers of MOFs play important roles in improving the CO2 capture ability by enhancing the CO2 sorption affinity. In this work, the functionalization effects on CO2 adsorption were systematically investigated by rationally incorporating various functional groups including −SO3H, −COOH, −NH2, −OH, −CN, −CH3 and −F into a MOF-177 template using computational methods. Asymmetries of electron density on the functionalized linkers were intensified, introducing significant enhancements of the CO2 adsorption ability of the modified MOF-177. In addition, three kinds of molecular interactions between CO2 and functional groups were analyzed and summarized in this work. Especially, our results reveal that −SO3H is the best-performing functional group for CO2 capture in MOFs, better than the widely used −NH2 or −F groups. The current study provides a novel route for future MOF modification toward CO2 capture.