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Multimodal Hard X-Ray Nanotomography Probes Pore Accessibility of Technical Catalysts after Coking

Weber, Sebastian ; Karpov, Dmitry ; Kahnt, Maik LU orcid ; Diaz, Ana ; Romanenko, Yuliia ; Kotrel, Stefan ; Haas, Andreas ; Hinrichsen, Bernd ; Bottke, Nils and Grunwaldt, Jan Dierk , et al. (2024) In ChemCatChem 16(22).
Abstract

Coking is a common catalyst deactivation route in industrial processes involving carbonaceous species. While coking is easy to diagnose, this is often performed by bulk analysis. Understanding specific symptoms such as pore blockage and obstruction of active sites is especially challenging for technical catalysts and requires a spatially-resolved approach. Here a combination of ptychographic X-ray computed tomography (PXCT) and X-ray fluorescence nanotomography (XRF-CT) could identify and allocate regions of coke deposition within a technical zeolite-based propane dehydrogenation catalyst. PXCT is sensitive to the quantitative electron density of the sample, therefore indirectly visualising coke deposition in meso- and macropores with... (More)

Coking is a common catalyst deactivation route in industrial processes involving carbonaceous species. While coking is easy to diagnose, this is often performed by bulk analysis. Understanding specific symptoms such as pore blockage and obstruction of active sites is especially challenging for technical catalysts and requires a spatially-resolved approach. Here a combination of ptychographic X-ray computed tomography (PXCT) and X-ray fluorescence nanotomography (XRF-CT) could identify and allocate regions of coke deposition within a technical zeolite-based propane dehydrogenation catalyst. PXCT is sensitive to the quantitative electron density of the sample, therefore indirectly visualising coke deposition in meso- and macropores with 56–61 nm 3D spatial resolution. For more direct visualisation the catalysts were treated with Cu solution as fluorescent marker, whereby complementary XRF-CT analysis could distinguish accessible and blocked pores based on the presence or absence of adsorbed Cu. This strategy was used to assess coking as a function of time on stream, to evaluate coke removal by oxidative regeneration, and to distinguish the presence of coke deposits separately within the zeolite and binder components. This strategy is applicable to virtually any porous solid catalyst and can deliver previously unknown insights into the common phenomenon of coke deposition particularly in technical catalysts.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Carbon, Heterogeneous catalysis, Synchrotron radiation, X-ray fluorescence, X-ray tomography
in
ChemCatChem
volume
16
issue
22
publisher
Wiley-VCH Verlag
external identifiers
  • scopus:85204730030
ISSN
1867-3880
DOI
10.1002/cctc.202301298
language
English
LU publication?
yes
additional info
Publisher Copyright: © 2024 The Author(s). ChemCatChem published by Wiley-VCH GmbH.
id
b2a712fe-feb6-44f8-a989-195b45cb5e04
date added to LUP
2024-10-02 08:32:07
date last changed
2025-04-04 15:20:53
@article{b2a712fe-feb6-44f8-a989-195b45cb5e04,
  abstract     = {{<p>Coking is a common catalyst deactivation route in industrial processes involving carbonaceous species. While coking is easy to diagnose, this is often performed by bulk analysis. Understanding specific symptoms such as pore blockage and obstruction of active sites is especially challenging for technical catalysts and requires a spatially-resolved approach. Here a combination of ptychographic X-ray computed tomography (PXCT) and X-ray fluorescence nanotomography (XRF-CT) could identify and allocate regions of coke deposition within a technical zeolite-based propane dehydrogenation catalyst. PXCT is sensitive to the quantitative electron density of the sample, therefore indirectly visualising coke deposition in meso- and macropores with 56–61 nm 3D spatial resolution. For more direct visualisation the catalysts were treated with Cu solution as fluorescent marker, whereby complementary XRF-CT analysis could distinguish accessible and blocked pores based on the presence or absence of adsorbed Cu. This strategy was used to assess coking as a function of time on stream, to evaluate coke removal by oxidative regeneration, and to distinguish the presence of coke deposits separately within the zeolite and binder components. This strategy is applicable to virtually any porous solid catalyst and can deliver previously unknown insights into the common phenomenon of coke deposition particularly in technical catalysts.</p>}},
  author       = {{Weber, Sebastian and Karpov, Dmitry and Kahnt, Maik and Diaz, Ana and Romanenko, Yuliia and Kotrel, Stefan and Haas, Andreas and Hinrichsen, Bernd and Bottke, Nils and Grunwaldt, Jan Dierk and Schunk, Stephan and Sheppard, Thomas L.}},
  issn         = {{1867-3880}},
  keywords     = {{Carbon; Heterogeneous catalysis; Synchrotron radiation; X-ray fluorescence; X-ray tomography}},
  language     = {{eng}},
  number       = {{22}},
  publisher    = {{Wiley-VCH Verlag}},
  series       = {{ChemCatChem}},
  title        = {{Multimodal Hard X-Ray Nanotomography Probes Pore Accessibility of Technical Catalysts after Coking}},
  url          = {{http://dx.doi.org/10.1002/cctc.202301298}},
  doi          = {{10.1002/cctc.202301298}},
  volume       = {{16}},
  year         = {{2024}},
}