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arXiv · 1904.11921

The Behavior of Flexible MIL-53(Al) upon CH4 and CO2 Adsorption

Anne Boutin·François-Xavier Coudert·Marie-Anne Springuel-Huet·Alexander V. Neimark·Gérard Férey·Alain H. Fuchs
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Abstract

The use of the osmotic thermodynamic model, combined with a series of methane and carbon dioxide gas adsorption experiments at various temperatures, has allowed shedding some new light on the fascinating phase behavior of flexible MIL-53(Al) metal-organic frameworks. A generic temperature-loading phase diagram has been derived; it is shown that the breathing effect in MIL-53 is a very general phenomenon, which should be observed in a limited temperature range regardless of the guest molecule. In addition, the previously proposed stress model for the structural transitions of MIL-53 is shown to be transferable from xenon to methane adsorption. The stress model also provides a theoretical framework for understanding the existence of lp/np phase mixtures at pressures close to the breathing transition pressure, without having to invoke an inhomogeneous distribution of the adsorbate in the porous sample.

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Anne Boutin, François-Xavier Coudert, Marie-Anne Springuel-Huet, Alexander V. Neimark, Gérard Férey, Alain H. Fuchs. 2019-04-26. The Behavior of Flexible MIL-53(Al) upon CH4 and CO2 Adsorption. https://doi.org/10.1021/jp108710h

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