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.

Graphical abstract

Keywords

metal-organic frameworks / functional groups / CO₂ capture / GCMC / DFT

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Higher Education Press