(494d) Exploration of Calf-20’s Structural Flexibility and CO2 Capture Performance in the Presence of Humidity Via Experiments and Simulations

In 2021, Svante reported successful scale up of an outstanding MOF material, CALF-20 with remarkable properties to capture CO₂ from flue gas while maintaining stability and resisting water¹. Here, we combine atomistic-level simulations with experiments to study adsorptive properties of CALF-20 and shed light on its flexible crystal structure. We compare measured and predicted CO₂ and water adsorption isotherms and explain the role of water-framework interactions and hydrogen bonding networks in CALF-20’s hydrophobic behaviour. Furthermore, regular and enhanced sampling molecular dynamics simulations are performed with both density-functional theory (DFT) and machine learning potentials (MLPs) trained to DFT energies and forces. From these simulations, the effects of adsorption-induced flexibility in CALF-20 are uncovered. We envisage this work would encourage development of other MOF materials useful for CO₂ capture applications.²

References:

1. J.-B. Lin, et al. Science 2021, 374, 1464–1469.

2. R. Oktavian et al. Nature Communications 2024, accepted.