Free and internal energies for the adsorption of short alkanes into the zeolite SSZ-13 from ab initio molecular dynamics simulations
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alkane-Q_rev2_v2.pdf
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2024-09-21
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Final Accepted Manuscript
Affiliation
Department of Biosystem Engineering, The University of ArizonaIssue Date
2023-09-21
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Royal Society of Chemistry (RSC)Citation
Hutton, D. J., & Göltl, F. (2023). Free and Internal Energies for the Adsorption of Short Alkanes into the Zeolite SSZ-13 from Ab Initio Molecular Dynamics Simulations.Rights
© the Owner Societies 2023.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
Electronic structure calculations have become a valuable tool in understanding chemical reactions of hydrocarbons in zeolite pores. However, commonly applied approaches to calculate free energies based on static electronic structure calculations significantly overestimate the entropic penalty for molecular adsorption into zeolite pores. Here, we use ab initio molecular dynamics (AIMD) simulations to model the adsorption of methane, ethane, and propane to purely siliceous and protonated SSZ-13. In our analyses we focus on the internal and Helmholtz free energies of adsorption of each molecule and compare our results to various approaches for the calculation of free energies based on static calculations. We find that only an approach that retains two thirds of the translational entropy of the adsorbate upon adsorption compares favorably with AIMD simulations. However, comparison to experimental measurements of Gibbs free energies of adsorption reported in the literature implies that we might not have captured the full complexity of alkane adsorption in our model. We expect that results in this work will help to develop a better understanding of alkane adsorption in zeolites, and that the provided data will serve as a benchmark for free energy calculations of alkane adsorption in zeolites in the future.Note
12 month embargo; first published: 21 September 2023ISSN
1463-9076EISSN
1463-9084Version
Final accepted manuscriptSponsors
University of Arizonaae974a485f413a2113503eed53cd6c53
10.1039/d3cp02523c