Logo des Repositoriums
Zur Startseite
  • English
  • Deutsch
Anmelden
  1. Startseite
  2. SuUB
  3. Forschungsdokumente
  4. The origin of a large apparent tortuosity factor for the Knudsen diffusion inside monoliths of a samaria-alumina aerogel catalyst: a diffusion NMR study
 
Zitierlink DOI
10.26092/elib/2457
Verlagslink DOI
10.1039/c5cp04609b

The origin of a large apparent tortuosity factor for the Knudsen diffusion inside monoliths of a samaria-alumina aerogel catalyst: a diffusion NMR study

Veröffentlichungsdatum
2015-09-23
Autoren
Mueller, R.  
Zhang, S.  
Klink, Miriam  
Bäumer, Marcus  
Vasenkov, S.  
Zusammenfassung
Pulsed field gradient (PFG) NMR was applied to measure tortuosity factors for carbon dioxide diffusion in the Knudsen and gas regimes inside monoliths of a samaria-alumina aerogel catalyst, a high porosity material containing micropores in addition to meso- and macropores. The apparent tortuosity factor obtained from PFG NMR measurements for the Knudsen diffusion in the meso- and macropores of the catalyst has an unexpectedly large value of approximately 6 if carbon dioxide adsorption in the micropores and other types of surface adsorption sites of the catalyst is ignored. At the same time, the corresponding apparent tortuosity factor in the gas regime was found to be around 2. Application of a proposed model which describes fast molecular exchange between the surface adsorption sites and the main pore volume of the catalyst yields corrected tortuosity factors which depend only on the pore system geometry. Using this model, the corrected tortuosity factors were found to be around 2 for both diffusion regimes, in agreement with the expectations based on a high porosity of the studied catalyst.
Schlagwörter
Mimenima
Verlag
RSC, Royal Society of Chemistry
Institution
Universität Bremen  
Fachbereich
Fachbereich 02: Biologie/Chemie (FB 02)  
Institute
Institut für angewandte und physikalische Chemie (IAPC)  
Dokumenttyp
Artikel/Aufsatz
Zeitschrift/Sammelwerk
Physical chemistry chemical physics (PCCP)  
Startseite
27481
Endseite
27487
Zweitveröffentlichung
Ja
Dokumentversion
Postprint
Lizenz
Alle Rechte vorbehalten
Sprache
Englisch
Dateien
Lade...
Vorschaubild
Name

R. Müller, S. Zhang, M. Klink, M. Bäumer, S. Vasenkov, The origin of a large apparant tortuosity for the Knudsen diffusion_2015_ accepted version_Deckblatt_pdfa1.pdf

Size

528.75 KB

Format

Adobe PDF

Checksum

(MD5):a7eff8df06af574cb69563cda5b6b978

Built with DSpace-CRIS software - Extension maintained and optimized by 4Science

  • Datenschutzbestimmungen
  • Endnutzervereinbarung
  • Feedback schicken