The Influence of Intrinsic Framework Flexibility on Adsorption in Nanoporous Materials (Data Download)

Authors: Matthew Witman1, Sanliang Ling2, Sudi Jawahery1, Peter G. Boyd3, Maciej Haranczyk4,5, Ben Slater2, Berend Smit1,3

  1. Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
  2. Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
  3. Laboratory of Molecular Simulation, Institut des Sciences et Ingénierie Chimiques, Valais, Ecole Polytechnique Fédérale de Lausanne (EPFL), Rue de l’Industrie 17, CH-1951 Sion, Switzerland
  4. Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
  5. IMDEA Materials Institute, C/Eric Kandel 2, 28906 Getafe, Madrid, Spain

DOI10.24435/materialscloud:2017.0003/v2 (version v2, submitted on 10 November 2018)

How to cite this entry

Matthew Witman, Sanliang Ling, Sudi Jawahery, Peter G. Boyd, Maciej Haranczyk, Ben Slater, Berend Smit, The Influence of Intrinsic Framework Flexibility on Adsorption in Nanoporous Materials (Data Download), Materials Cloud Archive (2018), doi: 10.24435/materialscloud:2017.0003/v2.

Description

Project Abstract: For applications of metal-organic frameworks (MOFs) such as gas storage and separation, flexibility is often seen as a parameter that can tune material performance. In this work we aim to determine the optimal flexibility for the shape selective separation of similarly sized molecules (e.g., Xe/Kr mixtures). To obtain systematic insight into how the flexibility impacts this type of separation we develop a simple analytical model that predicts a material's Henry regime adsorption and selectivity as a function of flexibility. We elucidate the complex dependence of selectivity on a framework's intrinsic flexibility whereby performance is either improved or reduced with increasing flexibility, depending on the material's pore size characteristics. However, the selectivity of a material with the pore size and chemistry that already maximizes selectivity in the rigid approximation is continuously diminished with increasing flexibility, demonstrating that the globally optimal separation exists within an entirely rigid pore. Molecular simulations show that our simple model predicts performance trends that are observed when screening the adsorption behavior of flexible MOFs. These flexible simulations provide better agreement with experimental adsorption data in a high performance material that is not captured when modeling this framework as rigid, an approximation typically made in high-throughput screening studies. We conclude that, for shape selective adsorption applications, the globally optimal material will have the optimal pore size/chemistry and minimal intrinsic flexibility even though other non-optimal materials' selectivity can actually be improved by flexibility. Equally important, we find that flexible simulations can be critical for correctly modeling adsorption in these types of systems.

About this entry: You can find the Xe/Kr Henry coefficients and the infinite dilution selectivity of more than 2000 CoRE MOF structures obtained via computational screening when materials are simulated as both flexible and rigid. For details about the methods used to obtain these results, please see the corresponding paper (DOI: 10.1021/jacs.7b01688). The data provided here was used to create the scatter plots presented in the original paper and can be used to find the adsorption properties for any material in the CoRE MOF screening.

Version 2 includes a minor formatting correction to make the CIF files compliant with the CIF standard.

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Files

File name Size Description
all_cifs.tar
MD5MD5: 86b48554c5f8ba6e1d853a78c2bcb7ba
3.6 MiB Crystallographic Information Files (CIFs) for structures of all metal-organic frameworks (MOFs) screened for Xe/Kr adsorption with rigid and flexible material models
final_XeKr_flex_data.dat
MD5MD5: 3b67309653deaa1a8cfda7400f449850
324.0 KiB Xe/Kr adsorption data for each MOF structure contained in all_cifs. The header line gives the type of data contained in each column.

License

Files and data are licensed under the terms of the following license: Creative Commons Attribution 4.0 International.

External references

Journal reference (Paper in which this data has been published)
Witman, M.; Ling, S.; Jawahery, S.; Boyd, P.G.; Haranczyk, M.; Slater, B.; Smit, B., JACS 2017, 139 (15), pp. 5547-57. doi:10.1021/jacs.7b01688

Keywords

Nanoporous materials Flexibility Xe/Kr separations

Version history

10 November 2018 [This version]

05 April 2017