---
_id: '55999'
abstract:
- lang: eng
  text: Clean hydrogen is a key aspect of carbon neutrality, necessitating robust
    methods for monitoring hydrogen concentration in critical infrastructures like
    pipelines or power plants. While semiconducting metal oxides such as In2O3 can
    monitor gas concentrations down to the ppm range, they often exhibit cross-sensitivity
    to other gases like H2O. In this study, we investigated whether cyclic optical
    illumination of a gas-sensitive In2O3 layer creates identifiable changes in a
    gas sensor´s electronic resistance that can be linked to H2 and H2O concentrations
    via machine learning. We exposed nanostructured In2O3 with a large surface area
    of 95 m2 g-1 to H2 concentrations (0-800 ppm) and relative humidity (0-70%) under
    cyclic activation utilizing blue light. The sensors were tested for 20 classes
    of gas combinations. A support vector machine achieved classification rates up
    to 92.0%, with reliable reproducibility (88.2 ± 2.7%) across five individual sensors
    using 10-fold cross-validation. Our findings suggest that cyclic optical activation
    can be used as a tool to classify H2 and H2O concentrations.
article_type: original
author:
- first_name: 'Dominik '
  full_name: 'Baier, Dominik '
  last_name: Baier
- first_name: 'Alexander '
  full_name: 'Krüger, Alexander '
  last_name: Krüger
- first_name: 'Thorsten '
  full_name: 'Wagner, Thorsten '
  last_name: Wagner
- first_name: Michael
  full_name: Tiemann, Michael
  id: '23547'
  last_name: Tiemann
  orcid: 0000-0003-1711-2722
- first_name: Christian
  full_name: Weinberger, Christian
  id: '11848'
  last_name: Weinberger
citation:
  ama: 'Baier D, Krüger A, Wagner T, Tiemann M, Weinberger C. Gas Sensing with Nanoporous
    In2O3 under Cyclic Optical Activation: Machine Learning-Aided Classification of
    H2 and H2O. <i>Chemosensors</i>. 2024;12(9):178. doi:<a href="https://doi.org/10.3390/chemosensors12090178">10.3390/chemosensors12090178</a>'
  apa: 'Baier, D., Krüger, A., Wagner, T., Tiemann, M., &#38; Weinberger, C. (2024).
    Gas Sensing with Nanoporous In2O3 under Cyclic Optical Activation: Machine Learning-Aided
    Classification of H2 and H2O. <i>Chemosensors</i>, <i>12</i>(9), 178. <a href="https://doi.org/10.3390/chemosensors12090178">https://doi.org/10.3390/chemosensors12090178</a>'
  bibtex: '@article{Baier_Krüger_Wagner_Tiemann_Weinberger_2024, title={Gas Sensing
    with Nanoporous In2O3 under Cyclic Optical Activation: Machine Learning-Aided
    Classification of H2 and H2O}, volume={12}, DOI={<a href="https://doi.org/10.3390/chemosensors12090178">10.3390/chemosensors12090178</a>},
    number={9}, journal={Chemosensors}, publisher={MDPI}, author={Baier, Dominik  and
    Krüger, Alexander  and Wagner, Thorsten  and Tiemann, Michael and Weinberger,
    Christian}, year={2024}, pages={178} }'
  chicago: 'Baier, Dominik , Alexander  Krüger, Thorsten  Wagner, Michael Tiemann,
    and Christian Weinberger. “Gas Sensing with Nanoporous In2O3 under Cyclic Optical
    Activation: Machine Learning-Aided Classification of H2 and H2O.” <i>Chemosensors</i>
    12, no. 9 (2024): 178. <a href="https://doi.org/10.3390/chemosensors12090178">https://doi.org/10.3390/chemosensors12090178</a>.'
  ieee: 'D. Baier, A. Krüger, T. Wagner, M. Tiemann, and C. Weinberger, “Gas Sensing
    with Nanoporous In2O3 under Cyclic Optical Activation: Machine Learning-Aided
    Classification of H2 and H2O,” <i>Chemosensors</i>, vol. 12, no. 9, p. 178, 2024,
    doi: <a href="https://doi.org/10.3390/chemosensors12090178">10.3390/chemosensors12090178</a>.'
  mla: 'Baier, Dominik, et al. “Gas Sensing with Nanoporous In2O3 under Cyclic Optical
    Activation: Machine Learning-Aided Classification of H2 and H2O.” <i>Chemosensors</i>,
    vol. 12, no. 9, MDPI, 2024, p. 178, doi:<a href="https://doi.org/10.3390/chemosensors12090178">10.3390/chemosensors12090178</a>.'
  short: D. Baier, A. Krüger, T. Wagner, M. Tiemann, C. Weinberger, Chemosensors 12
    (2024) 178.
date_created: 2024-09-03T13:49:42Z
date_updated: 2025-11-26T12:14:21Z
ddc:
- '540'
department:
- _id: '2'
- _id: '307'
doi: 10.3390/chemosensors12090178
file:
- access_level: closed
  content_type: application/pdf
  creator: cweinber
  date_created: 2024-09-03T13:58:18Z
  date_updated: 2024-09-03T13:58:18Z
  file_id: '56000'
  file_name: chemosensors-12-00178.pdf
  file_size: 3275869
  relation: main_file
  success: 1
file_date_updated: 2024-09-03T13:58:18Z
has_accepted_license: '1'
intvolume: '        12'
issue: '9'
keyword:
- resistive gas sensor
- chemiresistor
- semiconductor
- metal oxide
- In2O3
- mesoporous
- hydrogen
- humidtiy
- machine learning
- sustainable
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://www.mdpi.com/2227-9040/12/9/178
oa: '1'
page: '178'
publication: Chemosensors
publication_identifier:
  issn:
  - 2227-9040
publication_status: published
publisher: MDPI
quality_controlled: '1'
status: public
title: 'Gas Sensing with Nanoporous In2O3 under Cyclic Optical Activation: Machine
  Learning-Aided Classification of H2 and H2O'
type: journal_article
user_id: '11848'
volume: 12
year: '2024'
...
---
_id: '63956'
abstract:
- lang: eng
  text: The synthesis of novel robust and stable iridium-based immobilized catalysts
    on silica-polymer hybrid materials (Si-PB-Ir) is described. These catalysts are
    characterized by a combination of 1D P-31 CP-MAS and 2D P-31-H-1 HETCOR and J-resolved
    multinuclear solid state NMR experiments. Different binding situations such as
    singly and multiply coordinated phosphines are identified. Density functional
    theory (DFT) calculations are performed to corroborate the interpretation of the
    experimental NMR data, in order to propose a structural model of the heterogenized
    catalysts. Finally, the catalytic activity of the Si-PB-Ir catalysts is investigated
    for the hydrogenation of styrene employing para-enriched hydrogen gas.
author:
- first_name: Torsten
  full_name: Gutmann, Torsten
  id: '118165'
  last_name: Gutmann
- first_name: S.
  full_name: Alkhagani, S.
  last_name: Alkhagani
- first_name: N.
  full_name: Rothermel, N.
  last_name: Rothermel
- first_name: H. H.
  full_name: Limbach, H. H.
  last_name: Limbach
- first_name: H.
  full_name: Breitzke, H.
  last_name: Breitzke
- first_name: G.
  full_name: Buntkowsky, G.
  last_name: Buntkowsky
citation:
  ama: Gutmann T, Alkhagani S, Rothermel N, Limbach HH, Breitzke H, Buntkowsky G.
    P-31-Solid-State NMR Characterization and Catalytic Hydrogenation Tests of Novel
    heterogenized Iridium-Catalysts. <i>Zeitschrift Fur Physikalische Chemie-International
    Journal of Research in Physical Chemistry &#38; Chemical Physics</i>. 2017;231(3):653–669.
    doi:<a href="https://doi.org/10.1515/zpch-2016-0837">10.1515/zpch-2016-0837</a>
  apa: Gutmann, T., Alkhagani, S., Rothermel, N., Limbach, H. H., Breitzke, H., &#38;
    Buntkowsky, G. (2017). P-31-Solid-State NMR Characterization and Catalytic Hydrogenation
    Tests of Novel heterogenized Iridium-Catalysts. <i>Zeitschrift Fur Physikalische
    Chemie-International Journal of Research in Physical Chemistry &#38; Chemical
    Physics</i>, <i>231</i>(3), 653–669. <a href="https://doi.org/10.1515/zpch-2016-0837">https://doi.org/10.1515/zpch-2016-0837</a>
  bibtex: '@article{Gutmann_Alkhagani_Rothermel_Limbach_Breitzke_Buntkowsky_2017,
    title={P-31-Solid-State NMR Characterization and Catalytic Hydrogenation Tests
    of Novel heterogenized Iridium-Catalysts}, volume={231}, DOI={<a href="https://doi.org/10.1515/zpch-2016-0837">10.1515/zpch-2016-0837</a>},
    number={3}, journal={Zeitschrift Fur Physikalische Chemie-International Journal
    of Research in Physical Chemistry &#38; Chemical Physics}, author={Gutmann, Torsten
    and Alkhagani, S. and Rothermel, N. and Limbach, H. H. and Breitzke, H. and Buntkowsky,
    G.}, year={2017}, pages={653–669} }'
  chicago: 'Gutmann, Torsten, S. Alkhagani, N. Rothermel, H. H. Limbach, H. Breitzke,
    and G. Buntkowsky. “P-31-Solid-State NMR Characterization and Catalytic Hydrogenation
    Tests of Novel Heterogenized Iridium-Catalysts.” <i>Zeitschrift Fur Physikalische
    Chemie-International Journal of Research in Physical Chemistry &#38; Chemical
    Physics</i> 231, no. 3 (2017): 653–669. <a href="https://doi.org/10.1515/zpch-2016-0837">https://doi.org/10.1515/zpch-2016-0837</a>.'
  ieee: 'T. Gutmann, S. Alkhagani, N. Rothermel, H. H. Limbach, H. Breitzke, and G.
    Buntkowsky, “P-31-Solid-State NMR Characterization and Catalytic Hydrogenation
    Tests of Novel heterogenized Iridium-Catalysts,” <i>Zeitschrift Fur Physikalische
    Chemie-International Journal of Research in Physical Chemistry &#38; Chemical
    Physics</i>, vol. 231, no. 3, pp. 653–669, 2017, doi: <a href="https://doi.org/10.1515/zpch-2016-0837">10.1515/zpch-2016-0837</a>.'
  mla: Gutmann, Torsten, et al. “P-31-Solid-State NMR Characterization and Catalytic
    Hydrogenation Tests of Novel Heterogenized Iridium-Catalysts.” <i>Zeitschrift
    Fur Physikalische Chemie-International Journal of Research in Physical Chemistry
    &#38; Chemical Physics</i>, vol. 231, no. 3, 2017, pp. 653–669, doi:<a href="https://doi.org/10.1515/zpch-2016-0837">10.1515/zpch-2016-0837</a>.
  short: T. Gutmann, S. Alkhagani, N. Rothermel, H.H. Limbach, H. Breitzke, G. Buntkowsky,
    Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical
    Chemistry &#38; Chemical Physics 231 (2017) 653–669.
date_created: 2026-02-07T15:35:41Z
date_updated: 2026-02-17T16:18:04Z
doi: 10.1515/zpch-2016-0837
extern: '1'
intvolume: '       231'
issue: '3'
keyword:
- Chemistry
- dynamic nuclear-polarization
- solid-state nmr
- DFT
- heterogeneous catalysis
- hydrido complexes
- hydrogenation
- immobilized catalyst
- inorganic hybrid
- iridium
- materials
- mesoporous
- molecular-orbital methods
- PHIP
- phosphine complexes
- reusable catalysts
- silica
- solid-state-NMR
- wilkinsons catalyst
language:
- iso: eng
page: 653–669
publication: Zeitschrift Fur Physikalische Chemie-International Journal of Research
  in Physical Chemistry & Chemical Physics
publication_identifier:
  issn:
  - 0942-9352
status: public
title: P-31-Solid-State NMR Characterization and Catalytic Hydrogenation Tests of
  Novel heterogenized Iridium-Catalysts
type: journal_article
user_id: '100715'
volume: 231
year: '2017'
...
