Center for Molecular Modeling - B. Schmidt

In-Depth Thermodynamic and Kinetic Analysis of Ethane Diffusion in ZIF-8

bernd — Thu, 24 Oct 2024 07:52:55 +0000

B. Schmidt, P. Cnudde, V. Van Speybroeck, L. Vanduyfhuys

Journal of Physical Chemistry C

128, 43, 18509-18523

2024

Abstract

Flexible microporous ZIF-8 crystals show excellent separation behavior of small molecules such as ethaneand ethene. As such, hydrocarbon diffusion plays an essential role in the performance of these materials, yet determining accurate diffusion constants is nontrivial. Both ab initio and force-field based molecular dynamics simulations, coupled with umbrella sampling are applied in this work to characterize the diffusion of ethane in ZIF-8. Diffusion constants are extracted from the simulations by a combination of transition state theory and a random-walk hopping model, and are compared against experimentally measured values from literature. Ethane diffusion is a hindered process characterized by a transition state corresponding to an ethane molecule crossing the gate in between two neighboring cages formed by methylimidazole linkers. Free energy profiles of the diffusion process are derived and analyzed revealing the entropic nature of the barrier due to a counteracting of covalent host deformation energy and nonbonding host–guest interaction. A temperature analysis further confirms the entropic nature of the barrier and reveals an increased gate opening at increasing temperature. Finally, the loading dependency of diffusion is investigated revealing that increasing the ethane loading of the cages slightly slows down diffusion as a result of beneficial guest–guest interactions in the cages. Our findings yield essential elementary insight into how different molecular interactions influence the diffusion path of hydrocarbons throughout ZIF-8 crystals.

DOI

http://dx.doi.org/10.1021/acs.jpcc.4c04790

Private attachment

jp4c04790_si_001.pdf

schmidt-et-al-2024-in-depth-thermodynamic-and-kinetic-analysis-of-ethane-diffusion-in-zif-8.pdf

Diffusion of light olefins through ZIF-8 unraveled by machine learning potentials

bernd — Tue, 14 Oct 2025 10:53:23 +0000

B. Schmidt, L. Vanduyfhuys, Veronique Van Speybroeck

ISBN/ISSN:

Poster

Conference / event / venue

Conference Centre Leeuwenhorst in Noordwijkerhout - The Netherlands

Noordwijkerhout, Netherlands

Monday, 10 March, 2025 to Wednesday, 12 March, 2025

Abstract (private)

Abstract_NCCC_2025.pdf

A molecular dynamics study on light olefin diffusion in ZIF-8

bernd — Tue, 14 Oct 2025 10:46:19 +0000

B. Schmidt, L. Vanduyfhuys, Veronique Van Speybroeck

ISBN/ISSN:

Poster

Conference / event / venue

Chimie ParisTech / Université PSL

Paris, France

Tuesday, 23 May, 2023 to Wednesday, 24 May, 2023

Abstract (private)

Abstract_French_MOFs_2023-3.pdf

Light olefin diffusion in ZIF-8: A balance between enthalpy and entropy

bernd — Tue, 14 Oct 2025 10:43:06 +0000

B. Schmidt, L. Vanduyfhuys, Veronique Van Speybroeck

ISBN/ISSN:

Poster

Conference / event / venue

Granada Conference Center

Granada, Spain

Sunday, 24 September, 2023 to Wednesday, 27 September, 2023

Abstract (private)

EUROMOF2023_Abstract_LVDH[2639].pdf

Molecular simulation of alkane and alkene diffusion in nanoporous membranes to allow for an energy-efficient separation.

bernd — Thu, 08 Dec 2022 13:12:56 +0000

B. Schmidt, L. Vanduyfhuys, V. Van Speybroeck

ISBN/ISSN:

Poster

Conference / event / venue

Fears 2022

Gent + Belgium

Friday, 28 October, 2022

Abstract (private)

Summary for Poster-finale.pdf

Machines learning MOFs: training time-lagged autoencoders to learn collective variables for accurate free energy surfaces and transition kinetics

leen — Thu, 17 Mar 2022 13:35:58 +0000

Bernd Schmidt

leen — Tue, 26 Oct 2021 09:09:04 +0000