Hydrostable Fluorinated Metal–Organic Frameworks for CO<sub>2</sub> Capture from a Wet Flue Gas: Multiscale Computational Screening
Athulya S. Palakkal, Saad Aldin Mohamed, Jianwen Jiang
Abstract
High Resolution Image Download MS PowerPoint Slide Metal–organic frameworks (MOFs) are promising adsorbents for CO 2 capture due to readily tunable porosity and diverse functionality; however, their performance is deteriorated by the presence of H 2 O in a flue gas. Fluorinated MOFs (FMOFs) may impede H 2 O interaction with frameworks and enhance CO 2 adsorption under humid conditions. In this study, a multiscale computational screening study is reported to identify the top FMOFs for CO 2 capture from a wet flue gas. Initially, geometric properties as well as heats of H 2 O adsorption are used to shortlist FMOFs with a suitable pore size and weak H 2 O affinity. Then, grand-canonical Monte Carlo simulations are conducted for adsorption of a CO 2 /N 2 /H 2 O mixture with 60% relative humidity in 5061 FMOFs. Based on the adsorption performance, 19 FMOFs are identified as top candidates. It is revealed that the position of F atom, rather than the amount, affects CO 2 adsorption; moreover, N-decorated FMOFs are preferential for selective CO 2 adsorption. Finally, the hydrostability of the top FMOFs is confirmed by first-principles molecular dynamics simulations. From a microscopic level, this study provides quantitative structure–performance relationships, discovers hydrostable FMOFs with high CO 2 capture performance from a wet flue gas, and would facilitate the development of new MOFs toward efficient CO 2 capture under humid conditions.