The adsorption of methanol and water on SAPO-34: in situ and ex situ X-ray diffraction studies

David S. Wragg, Rune Johnsen, Poul Norby, Helmer Fjellwåg

    Research output: Contribution to journalJournal articleResearchpeer-review

    Abstract

    The adsorption of methanol on SAPO-34 has been studied using a combination of in situ synchrotron powder X-ray diffraction to follow the process and ex situ high resolution powder diffraction to determine the structure. The unit cell volume of SAPO-34 is found to expand by 0.5% during methanol adsorption displaying greater flexibility than silicalite under similar conditions. When water is adsorbed onto the framework it contracts, while the non-polar polymethylbenzene intermediates in the methanol to olefin process cause a significant expansion. We therefore suggest that the expansion (water <methanol <polymethylbenzenes) is linked to the strength of interaction with the framework and size of the adsorbent. The position of the methanol molecule has been determined from high resolution powder diffraction data. The oxygen to framework contacts are slightly longer than reported elsewhere for adsorbed water molecules on the same framework, supporting the observation from the in situ data that water is more strongly bound than methanol. The results are consistent with previous results from thermodynamic and tapered element oscillating microbalance measurements.
    Original languageEnglish
    JournalMicroporous and Mesoporous Materials
    Volume134
    Issue number1-3
    Pages (from-to)210-215
    ISSN1387-1811
    DOIs
    Publication statusPublished - 2010

    Keywords

    • Batteries and carbon-free energy storage
    • Materials and energy storage

    Cite this

    @article{8a276d8f421b44f5852a78273290078c,
    title = "The adsorption of methanol and water on SAPO-34: in situ and ex situ X-ray diffraction studies",
    abstract = "The adsorption of methanol on SAPO-34 has been studied using a combination of in situ synchrotron powder X-ray diffraction to follow the process and ex situ high resolution powder diffraction to determine the structure. The unit cell volume of SAPO-34 is found to expand by 0.5{\%} during methanol adsorption displaying greater flexibility than silicalite under similar conditions. When water is adsorbed onto the framework it contracts, while the non-polar polymethylbenzene intermediates in the methanol to olefin process cause a significant expansion. We therefore suggest that the expansion (water <methanol <polymethylbenzenes) is linked to the strength of interaction with the framework and size of the adsorbent. The position of the methanol molecule has been determined from high resolution powder diffraction data. The oxygen to framework contacts are slightly longer than reported elsewhere for adsorbed water molecules on the same framework, supporting the observation from the in situ data that water is more strongly bound than methanol. The results are consistent with previous results from thermodynamic and tapered element oscillating microbalance measurements.",
    keywords = "Batteries and carbon-free energy storage, Materials and energy storage, Batterier og kulstoffri kemisk energilagring, Materialer og energilagring",
    author = "Wragg, {David S.} and Rune Johnsen and Poul Norby and Helmer Fjellw{\aa}g",
    year = "2010",
    doi = "10.1016/j.micromeso.2010.06.002",
    language = "English",
    volume = "134",
    pages = "210--215",
    journal = "Microporous and Mesoporous Materials",
    issn = "1387-1811",
    publisher = "Elsevier",
    number = "1-3",

    }

    The adsorption of methanol and water on SAPO-34: in situ and ex situ X-ray diffraction studies. / Wragg, David S.; Johnsen, Rune; Norby, Poul; Fjellwåg, Helmer.

    In: Microporous and Mesoporous Materials, Vol. 134, No. 1-3, 2010, p. 210-215.

    Research output: Contribution to journalJournal articleResearchpeer-review

    TY - JOUR

    T1 - The adsorption of methanol and water on SAPO-34: in situ and ex situ X-ray diffraction studies

    AU - Wragg, David S.

    AU - Johnsen, Rune

    AU - Norby, Poul

    AU - Fjellwåg, Helmer

    PY - 2010

    Y1 - 2010

    N2 - The adsorption of methanol on SAPO-34 has been studied using a combination of in situ synchrotron powder X-ray diffraction to follow the process and ex situ high resolution powder diffraction to determine the structure. The unit cell volume of SAPO-34 is found to expand by 0.5% during methanol adsorption displaying greater flexibility than silicalite under similar conditions. When water is adsorbed onto the framework it contracts, while the non-polar polymethylbenzene intermediates in the methanol to olefin process cause a significant expansion. We therefore suggest that the expansion (water <methanol <polymethylbenzenes) is linked to the strength of interaction with the framework and size of the adsorbent. The position of the methanol molecule has been determined from high resolution powder diffraction data. The oxygen to framework contacts are slightly longer than reported elsewhere for adsorbed water molecules on the same framework, supporting the observation from the in situ data that water is more strongly bound than methanol. The results are consistent with previous results from thermodynamic and tapered element oscillating microbalance measurements.

    AB - The adsorption of methanol on SAPO-34 has been studied using a combination of in situ synchrotron powder X-ray diffraction to follow the process and ex situ high resolution powder diffraction to determine the structure. The unit cell volume of SAPO-34 is found to expand by 0.5% during methanol adsorption displaying greater flexibility than silicalite under similar conditions. When water is adsorbed onto the framework it contracts, while the non-polar polymethylbenzene intermediates in the methanol to olefin process cause a significant expansion. We therefore suggest that the expansion (water <methanol <polymethylbenzenes) is linked to the strength of interaction with the framework and size of the adsorbent. The position of the methanol molecule has been determined from high resolution powder diffraction data. The oxygen to framework contacts are slightly longer than reported elsewhere for adsorbed water molecules on the same framework, supporting the observation from the in situ data that water is more strongly bound than methanol. The results are consistent with previous results from thermodynamic and tapered element oscillating microbalance measurements.

    KW - Batteries and carbon-free energy storage

    KW - Materials and energy storage

    KW - Batterier og kulstoffri kemisk energilagring

    KW - Materialer og energilagring

    U2 - 10.1016/j.micromeso.2010.06.002

    DO - 10.1016/j.micromeso.2010.06.002

    M3 - Journal article

    VL - 134

    SP - 210

    EP - 215

    JO - Microporous and Mesoporous Materials

    JF - Microporous and Mesoporous Materials

    SN - 1387-1811

    IS - 1-3

    ER -