[article]
Titre : |
NO (or NH3) + O2 adsorption on fluorine-doped vanadia/titania and its role in the mechanism of a two - step process characterized by EPR |
Type de document : |
texte imprimé |
Auteurs : |
Qin Zhong, Auteur ; Tianjiao Zhang, Auteur ; Yuntao Li, Auteur |
Année de publication : |
2012 |
Article en page(s) : |
pp.390–395 |
Note générale : |
Génie chimique |
Langues : |
Anglais (eng) |
Mots-clés : |
Low-temperature selective catalytic reduction F-doping Vanadia/titania Superoxide ions |
Résumé : |
This study aimed at elucidating a two-step process of the low-temperature selective catalytic reduction (SCR) reaction. The data were collected through studying the EPR signal of NO (or NH3) + O2 adsorption on fluorine-doped vanadia/titania and vanadia/titania catalysts used for SCR reaction, as well as the impact of SO2 and H2O added to the gas mixtures. The EPR experiments provided a new method to explain the SCR reaction, which were associated with NO (NH3) + O2 reacting systems and had been inferred step by step. In summary, the first step of the two-step process was that the vanadium sites were reduced by NO or NH3 as electron donor; then, the superoxide ions appeared over vanadium.
The experimental findings showed that the surface acidity, surface oxygen vacancies and the superoxide could be increased by fluorine doping, accordingly, the two-step process rate would be enhanced by F doping. It was the reason for F-doped catalyst had the higher catalytic activity than vanadia/titania. This two-step process could also be used to elucidate the inhibition mechanism of SO2 and H2O for the SCR reaction. |
ISSN : |
1385-8947 |
En ligne : |
http://www.sciencedirect.com/science/article/pii/S1385894711010734 |
in Chemical engineering journal > Vol. 174 N° 1 (Octobre 2011) . - pp.390–395
[article] NO (or NH3) + O2 adsorption on fluorine-doped vanadia/titania and its role in the mechanism of a two - step process characterized by EPR [texte imprimé] / Qin Zhong, Auteur ; Tianjiao Zhang, Auteur ; Yuntao Li, Auteur . - 2012 . - pp.390–395. Génie chimique Langues : Anglais ( eng) in Chemical engineering journal > Vol. 174 N° 1 (Octobre 2011) . - pp.390–395
Mots-clés : |
Low-temperature selective catalytic reduction F-doping Vanadia/titania Superoxide ions |
Résumé : |
This study aimed at elucidating a two-step process of the low-temperature selective catalytic reduction (SCR) reaction. The data were collected through studying the EPR signal of NO (or NH3) + O2 adsorption on fluorine-doped vanadia/titania and vanadia/titania catalysts used for SCR reaction, as well as the impact of SO2 and H2O added to the gas mixtures. The EPR experiments provided a new method to explain the SCR reaction, which were associated with NO (NH3) + O2 reacting systems and had been inferred step by step. In summary, the first step of the two-step process was that the vanadium sites were reduced by NO or NH3 as electron donor; then, the superoxide ions appeared over vanadium.
The experimental findings showed that the surface acidity, surface oxygen vacancies and the superoxide could be increased by fluorine doping, accordingly, the two-step process rate would be enhanced by F doping. It was the reason for F-doped catalyst had the higher catalytic activity than vanadia/titania. This two-step process could also be used to elucidate the inhibition mechanism of SO2 and H2O for the SCR reaction. |
ISSN : |
1385-8947 |
En ligne : |
http://www.sciencedirect.com/science/article/pii/S1385894711010734 |
|