Induced effect of tungsten incorporation ...
Document type :
Article dans une revue scientifique
Permalink :
Title :
Induced effect of tungsten incorporation on the catalytic properties of CeVO 4 systems for the selective reduction of NO x by ammonia
Author(s) :
Gillot, Sylvain [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Tricot, Gregory [Auteur]
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement (LASIRE) - UMR 8516
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 [LASIRE]
Vezin, Herve [Auteur]
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 [LASIRE]
Dacquin, Jean-Philippe [Auteur]
Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Dujardin, Christophe [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Granger, Pascal [Auteur]
Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Tricot, Gregory [Auteur]

Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement (LASIRE) - UMR 8516
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 [LASIRE]
Vezin, Herve [Auteur]

Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 [LASIRE]
Dacquin, Jean-Philippe [Auteur]

Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Dujardin, Christophe [Auteur]

Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Granger, Pascal [Auteur]

Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Journal title :
Applied Catalysis B: Environmental
Volume number :
234
Pages :
318-328
Publisher :
Elsevier
Publication date :
2018-10-15
English keyword(s) :
Ammonia
CeV1-xWxO4
mixed oxides
Fast-SCR
Selective catalytic reduction
NOx
CeV1-xWxO4
mixed oxides
Fast-SCR
Selective catalytic reduction
NOx
HAL domain(s) :
Chimie/Catalyse
English abstract : [en]
The SCR performances of aged W-doped CeVO4 catalysts were investigated in fast-, NO2- and standard conditions. Bulk CeV1-xWxO4 catalysts were prepared in soft conditions, according to a hydrothermal synthesis route at ...
Show more >The SCR performances of aged W-doped CeVO4 catalysts were investigated in fast-, NO2- and standard conditions. Bulk CeV1-xWxO4 catalysts were prepared in soft conditions, according to a hydrothermal synthesis route at 180 °C leading to the ad hoc tetragonal structure. The aging procedure consisted in exposing the samples to 10 vol.% H2O diluted in air at 600 °C. The impact of this aging process was investigated as a function of tungsten loading, with x varying in the range 0.02–0.15. A clear beneficial effect is distinguishable at high temperature, i.e., above 300 °C, associated to a sharp selectivity enhancement irrespective of the operating conditions and tungsten loading. On the contrary, a slight detrimental effect on the reaction rate is clearly discernible in standard-conditions below 300 °C. It was found that the thermal aging induces more extensive diffusion of V5+ species assisted by the presence of substituted W6+. It was also demonstrated that tungsten diffuses more readily than V5+ leading ultimately to a significant surface enrichment and the formation of Ce4W9O33 mixed oxide evidenced from XRD and Raman spectroscopy. Hence, tungsten would rather act as a stabilizer than promoter avoiding the sintering of monomeric VOx species to more active polyvanadate species but also less selective. The gain observed in selectivity at high temperature can be equally explained by a greater stabilization of Brønsted acid sites and the preservation of the dispersion of monomeric vanadate species preventing the occurrence of ammonia oxidation.Show less >
Show more >The SCR performances of aged W-doped CeVO4 catalysts were investigated in fast-, NO2- and standard conditions. Bulk CeV1-xWxO4 catalysts were prepared in soft conditions, according to a hydrothermal synthesis route at 180 °C leading to the ad hoc tetragonal structure. The aging procedure consisted in exposing the samples to 10 vol.% H2O diluted in air at 600 °C. The impact of this aging process was investigated as a function of tungsten loading, with x varying in the range 0.02–0.15. A clear beneficial effect is distinguishable at high temperature, i.e., above 300 °C, associated to a sharp selectivity enhancement irrespective of the operating conditions and tungsten loading. On the contrary, a slight detrimental effect on the reaction rate is clearly discernible in standard-conditions below 300 °C. It was found that the thermal aging induces more extensive diffusion of V5+ species assisted by the presence of substituted W6+. It was also demonstrated that tungsten diffuses more readily than V5+ leading ultimately to a significant surface enrichment and the formation of Ce4W9O33 mixed oxide evidenced from XRD and Raman spectroscopy. Hence, tungsten would rather act as a stabilizer than promoter avoiding the sintering of monomeric VOx species to more active polyvanadate species but also less selective. The gain observed in selectivity at high temperature can be equally explained by a greater stabilization of Brønsted acid sites and the preservation of the dispersion of monomeric vanadate species preventing the occurrence of ammonia oxidation.Show less >
Language :
Anglais
Peer reviewed article :
Oui
Audience :
Internationale
Popular science :
Non
Administrative institution(s) :
ENSCL
Université de Lille
CNRS
Centrale Lille
Univ. Artois
Université de Lille
CNRS
Centrale Lille
Univ. Artois
Collections :
Research team(s) :
Matériaux pour la catalyse (MATCAT)
Remédiation et matériaux catalytiques (REMCAT)
Propriétés magnéto structurales des matériaux (PMSM)
Remédiation et matériaux catalytiques (REMCAT)
Propriétés magnéto structurales des matériaux (PMSM)
Submission date :
2019-09-25T14:37:55Z
2021-03-17T11:45:06Z
2021-03-17T11:45:06Z