Title :

Morphology oriented zro2 supported vanadium oxide for nh3-scr process: importance of structural and textural properties

Author(s) :

Liu, Shanshan [Auteur]
Beijing University of Chemical Technology [BUCT]
Wang, Hao [Auteur]
Beijing University of Chemical Technology [BUCT]
Wei, Ying [Auteur]
Beijing University of Chemical Technology [BUCT]
Zhang, Runduo [Auteur]
Beijing University of Chemical Technology [BUCT]
Royer, sebastien [Auteur]
Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181

Journal title :

ACS Applied Materials & Interfaces

Abbreviated title :

ACS Appl Mater Interfaces

Publication date :

2019-05-24

ISSN :

1944-8252

English keyword(s) :

NO
vanadium oxide
monoclinic
tetragonal
morphology
zirconia
NH3-SCR

HAL domain(s) :

Chimie/Catalyse

English abstract : [en]

ZrO2 supports, with diverse morphologies (hollow sphere, star, rod, mesoporous), were produced using hydrothermal and evaporation-induced self-assembly methods. Zirconia-supported vanadium oxide catalysts were prepared by ...
Show more >ZrO2 supports, with diverse morphologies (hollow sphere, star, rod, mesoporous), were produced using hydrothermal and evaporation-induced self-assembly methods. Zirconia-supported vanadium oxide catalysts were prepared by wet impregnation and used for the low-temperature selective catalytic reduction (SCR) of NO with ammonia. Characterization of catalysts includes N2 physisorption, elementary analysis, X-ray diffraction, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, temperature-programmed reduction by H2, and temperature-programmed desorption of NH3. Significant differences in terms of activity are measured. 3 wt % V2O5 supported on mesoporous ZrO2 (V/MZ) presents excellent N2 yields (>90%, in the 200-400 °C interval), with a wide operating temperature window (NO conversion > 95%, in the 225-425 °C interval), and less interesting performances were obtained when vanadium oxide is supported over stars, hollow spheres, and rods. Surface characterization showed a content of tetravalent vanadium ion, when supported, decreasing in the order of mesoporous > hollow sphere > star > rod. This order is in perfect agreement with the order of performance of the catalyst in the NH3-SCR reaction. The impact of tetravalent ion's presence on the surface is confirmed by diffuse reflectance infrared Fourier transform spectroscopy analysis, Brønsted acid sites generated on the surface, and the V4+-OH species involved in the reaction. The production of more important nitrite species over the tetragonal supported vanadium oxide catalyst could be another reason for the excellent NH3-SCR performance displayed by the V/MZ catalyst. When supported over monoclinic zirconia, like vanadium oxide over star-type morphology, the adsorbed NH3 species (NH4+ and coordinated NH3) reacted with NO x adsorption species (nitrate) to form ammonium nitrate. Ammonium nitrate can be decomposed to N2 and N2O (or NO2). Thus, NO conversion curves and N2 yield curves over tetragonal zirconia (MZ) at lower temperature were ahead of those over V/star ZrO2 because of the higher V4+ surface content and more active B acid sites associated with an easy formation of the nitrito intermediate.Show less >

Language :

Anglais

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

CNRS
Centrale Lille
ENSCL
Univ. Artois
Université de Lille

Collections :

• Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181

Research team(s) :

Matériaux pour la catalyse (MATCAT)

Submission date :

2022-03-02T07:13:56Z
2024-02-06T14:50:29Z