Evolution of VOx on TiO2-ZSM-5 Composite Supports upon K Poisoning and Its Effects on Ultralow Temperature NH3-SCR
Compared with V2O5/TiO2, vanadia catalysts supported on TiO2-ZSM-5 composite support possess excellent resistance to potassium poisoning in the selective catalytic reduction of NO by NH3 (NH3-SCR). Appropriate addition of ZSM-5 (10 wt %) enhances the low-temperature activity of NH3-SCR with more tha...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1985. - 41(2025), 10 vom: 18. März, Seite 6774-6788 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2025
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| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article |
| Zusammenfassung: | Compared with V2O5/TiO2, vanadia catalysts supported on TiO2-ZSM-5 composite support possess excellent resistance to potassium poisoning in the selective catalytic reduction of NO by NH3 (NH3-SCR). Appropriate addition of ZSM-5 (10 wt %) enhances the low-temperature activity of NH3-SCR with more than 80% NOx conversion at 175-450 °C, as the combination of TiO2 and ZSM-5 is conducive to the formation of more low-valent (polymeric) VOx preferentially deposited on TiO2. Compared with V2O5/TiO2, the composite support catalysts effectively shield V2O5 as the main active species from K poisoning by preferential ion-exchange of K+ with Brønsted acid sites (Si-O(H)-Al) of ZSM-5. According to physicochemical characterizations, the mechanism of catalyst deactivation is mainly attributed to excessive aggregation of VOx to form inactive crystalline V2O5 in addition to KVO3. In situ diffuse reflectance infrared Fourier transform spectroscopy indicates that the presence of K leads to the formation of inactive bidentate nitrates instead of active bridged nitrates. A novel vanadium-based catalyst with high alkali poisoning resistance for ultralow temperature (<200 °C) denitration was developed |
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| Beschreibung: | Date Revised 18.03.2025 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 1520-5827 |
| DOI: | 10.1021/acs.langmuir.4c05011 |