bei Google ScholarTitelangaben
Chen, Peirong ; Schönebaum, Simon ; Rauch, Dieter ; Moos, Ralf ; Simon, Ulrich:
Molecular understanding of catalyst as sensor : an in situ impedance-DRIFT
spectroscopy study of NH3-SCR reaction on zeolites.
2016
Veranstaltung: EMRS Spring Meeting 2016
, 2.5.-6.5.2016
, Lille, France.
(Veranstaltungsbeitrag: Kongress/Konferenz/Symposium/Tagung
,
Vortrag
)
Abstract
Selective catalytic reduction of nitrogen oxides (NOx) by NH3 (NH3-SCR) is one of the most promising strategies for the abatement of NOx emissions from diesel engines. To further improve the efficiency of NH3-SCR, it is necessary to get insights into the real-time state of the applied catalysts (mostly zeolite-based) under operational conditions. As revealed in our previous studies by impedance spectroscopy (IS), the proton transport in H-ZSM-5 was supported by stored NH3 as a solvate molecule, which allows H-ZSM-5 zeolites to be used in the sensing of both gas-phase NH3 and NH3-SCR reactions. Here, we performed in situ IS studies on highly comparable zeolites Fe-ZSM-5 and Cu-ZSM-5 (with the Cu or Fe species predominantly in isolated state) as catalysts and sensors simultaneously under SCR-related conditions. While the SCR conversion of stored NH3 on Fe-ZSM-5 can be effectively monitored based on NH3-supported proton transport, the sensing of SCR conversion of stored NH3 on Cu-ZSM-5 was significantly influenced by the formation of intermediates. Simultaneous IS and DRIFTS (diffuse reflection infrared Fourier transform spectroscopy) studies revealed that ammonium ions formed immediately by exposing NH3-saturated Cu-ZSM-5 to NO-containing atmospheres, and subsequently dominated the proton conductivity. Such a correlation of integral electrical response with molecular processes, achieved by our IS-DRIFTS studies, not only clarifies the molecular origin of the NH3-SCR sensing effect, but also provides a new perspective to understand the NH3-SCR mechanism over metal-promoted zeolites.
Weitere Angaben
| Publikationsform: | Veranstaltungsbeitrag (Vortrag) |
|---|---|
| Begutachteter Beitrag: | Ja |
| Institutionen der Universität: | Fakultäten > Fakultät für Ingenieurwissenschaften Fakultäten > Fakultät für Ingenieurwissenschaften > Lehrstuhl Funktionsmaterialien > Lehrstuhl Funktionsmaterialien - Univ.-Prof. Dr.-Ing. Ralf Moos Profilfelder > Advanced Fields > Neue Materialien Forschungseinrichtungen > Forschungszentren > Bayreuther Materialzentrum - BayMAT Fakultäten Fakultäten > Fakultät für Ingenieurwissenschaften > Lehrstuhl Funktionsmaterialien Profilfelder Profilfelder > Advanced Fields Forschungseinrichtungen Forschungseinrichtungen > Forschungszentren |
| Titel an der UBT entstanden: | Ja |
| Themengebiete aus DDC: | 600 Technik, Medizin, angewandte Wissenschaften > 620 Ingenieurwissenschaften |
| Eingestellt am: | 17 Mai 2016 08:23 |
| Letzte Änderung: | 17 Mai 2016 08:23 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/32386 |