Shen, Jun ; Hess, Christian (2021)
High Surface Area VOₓ/TiO₂/SBA-15 Model Catalysts for Ammonia SCR Prepared by Atomic Layer Deposition.
In: Catalysts, 2020, 10 (12)
doi: 10.26083/tuprints-00019276
Artikel, Zweitveröffentlichung, Verlagsversion
Kurzbeschreibung (Abstract)
The mode of operation of titania-supported vanadia (VOₓ) catalysts for NOx abatement using ammonia selective catalytic reduction (NH₃-SCR) is still vigorously debated. We introduce a new high surface area VOₓ/TiO₂/SBA-15 model catalyst system based on mesoporous silica SBA-15 making use of atomic layer deposition (ALD) for controlled synthesis of titania and vanadia multilayers. The bulk and surface structure is characterized by X-ray diffraction (XRD), UV-vis and Raman spectroscopy, as well as X-ray photoelectron spectroscopy (XPS), revealing the presence of dispersed surface VOx species on amorphous TiO₂ domains on SBA-15, forming hybrid Si–O–V and Ti–O–V linkages. Temperature-dependent analysis of the ammonia SCR catalytic activity reveals NOx conversion levels of up to ~60%. In situ and operando diffuse reflection IR Fourier transform (DRIFT) spectroscopy shows N–Hstretching modes, representing adsorbed ammonia and -NH₂ and -NH intermediate structures on Bronsted and Lewis acid sites. Partial Lewis acid sites with adjacent redox sites are proposed as the active sites and desorption of product molecules as the rate-determining step at low temperature. The high NOₓ conversion is attributed to the presence of highly dispersed VOₓ species and the moderate acidity of VOₓ supported on TiO₂/SBA-15.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2021 |
| Autor(en): | Shen, Jun ; Hess, Christian |
| Art des Eintrags: | Zweitveröffentlichung |
| Titel: | High Surface Area VOₓ/TiO₂/SBA-15 Model Catalysts for Ammonia SCR Prepared by Atomic Layer Deposition |
| Sprache: | Englisch |
| Publikationsjahr: | 2021 |
| Publikationsdatum der Erstveröffentlichung: | 2020 |
| Verlag: | MDPI |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Catalysts |
| Jahrgang/Volume einer Zeitschrift: | 10 |
| (Heft-)Nummer: | 12 |
| Kollation: | 25 Seiten |
| DOI: | 10.26083/tuprints-00019276 |
| URL / URN: | https://tuprints.ulb.tu-darmstadt.de/19276 |
| Zugehörige Links: | |
| Herkunft: | Zweitveröffentlichung aus gefördertem Golden Open Access |
| Kurzbeschreibung (Abstract): | The mode of operation of titania-supported vanadia (VOₓ) catalysts for NOx abatement using ammonia selective catalytic reduction (NH₃-SCR) is still vigorously debated. We introduce a new high surface area VOₓ/TiO₂/SBA-15 model catalyst system based on mesoporous silica SBA-15 making use of atomic layer deposition (ALD) for controlled synthesis of titania and vanadia multilayers. The bulk and surface structure is characterized by X-ray diffraction (XRD), UV-vis and Raman spectroscopy, as well as X-ray photoelectron spectroscopy (XPS), revealing the presence of dispersed surface VOx species on amorphous TiO₂ domains on SBA-15, forming hybrid Si–O–V and Ti–O–V linkages. Temperature-dependent analysis of the ammonia SCR catalytic activity reveals NOx conversion levels of up to ~60%. In situ and operando diffuse reflection IR Fourier transform (DRIFT) spectroscopy shows N–Hstretching modes, representing adsorbed ammonia and -NH₂ and -NH intermediate structures on Bronsted and Lewis acid sites. Partial Lewis acid sites with adjacent redox sites are proposed as the active sites and desorption of product molecules as the rate-determining step at low temperature. The high NOₓ conversion is attributed to the presence of highly dispersed VOₓ species and the moderate acidity of VOₓ supported on TiO₂/SBA-15. |
| Status: | Verlagsversion |
| URN: | urn:nbn:de:tuda-tuprints-192766 |
| Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 500 Naturwissenschaften und Mathematik > 540 Chemie |
| Fachbereich(e)/-gebiet(e): | 07 Fachbereich Chemie 07 Fachbereich Chemie > Eduard Zintl-Institut > Fachgebiet Anorganische Chemie 07 Fachbereich Chemie > Eduard Zintl-Institut > Fachgebiet Physikalische Chemie |
| Hinterlegungsdatum: | 09 Aug 2021 08:06 |
| Letzte Änderung: | 17 Aug 2021 06:38 |
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