Title :

Mechanistic insight into the methanol selective catalytic reduction of no reaction over cu-containing perovskites

Author(s) :

Wang, Hao [Auteur]
Beijing University of Chemical Technology [BUCT]
Zhang, Runduo [Auteur]
Beijing University of Chemical Technology [BUCT]
Li, Peixin [Auteur]
Beijing University of Chemical Technology [BUCT]
Royer, sebastien [Auteur]
Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181
Dacquin, Jean-Philippe [Auteur]
Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181

Journal title :

Journal of Catalysis

Abbreviated title :

J. Catal.

Volume number :

377

Pages :

480-493

Publication date :

2019-09-01

ISSN :

0021-9517

Keyword(s) :

Reaction mechanism
CH3OH SCR
Perovskite
LaFe0.8Cu0.2O3
In situ diffuse reflectance infrared Fourier transform spectroscopy
Density functional theory

HAL domain(s) :

Chimie/Catalyse

English abstract : [en]

The selective catalytic reduction (SCR) of NO by methanol was studied on LaFe0.8Cu0.2O3, and compared with that on an Ag/Al2O3 reference catalyst. A detailed characterization of the catalyst’s physicochemical properties ...
Show more >The selective catalytic reduction (SCR) of NO by methanol was studied on LaFe0.8Cu0.2O3, and compared with that on an Ag/Al2O3 reference catalyst. A detailed characterization of the catalyst’s physicochemical properties was carried out by X-ray diffraction, N2 physisorption, H2 temperature-programmed reduction, isotopic exchange experiments, NOads + O2ads temperature-programmed desorption, and X-ray photoelectron spectroscopy. Materials reactivity was investigated in the CH3OH-SCR of NO. The LaFe0.8Cu0.2O3 catalytic system, modified using reactive grinding (Cu-RG), exhibits the best catalytic performance in terms of both NO conversion (95% at 450 °C) and N2 yield (YN2 ≈ 93%). Activity is related to low-temperature Cu2+ redox activation, and a strong improvement of structural Fe3+ reducibility occurs with substitution of the structure. In contrast, Ag/Al2O3 was confirmed to be close to inactive in the studied temperature range. To elucidate the main reaction pathways over the two catalysts, in situ diffuse reflectance infrared Fourier transform spectroscopy was performed to determine the nature of the adsorbed species and surface intermediates involved. Over Cu-containing perovskite, CH3OH is observed to form methoxy species (single bondOsingle bondCH3). The surface adNOx species observed over Cu-RG are mainly reactive nitrite/nitrate species, which further reacted with single bondOsingle bondCH3 species to form formohydroxamic acid and carboxylate. In the case of Ag/Al2O3, nitrate species continuously accumulated over the alumina surface, on which dehydration of CH3OH indubitably occurs. Therefore, no enolic intermediate of SCR can be observed over Ag/Al2O3. A reaction mechanism over LaFe0.8Cu0.2O3 was finally proposed, supported by density functional theory calculations, in which Csingle bondN bond coupling accompanied by the first H transfer step is identified as the crucial step for N2 production in the CH3OH-SCR process over Cu-containing perovskites.Show less >

Language :

Anglais

Peer reviewed article :

Oui

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 :

2022-03-02T07:14:06Z
2024-01-15T16:28:45Z