Understanding the Catalytic Deactivation upon Hydrothermal Aging at 850 °C of WO<sub>3</sub>/Fe-Cu-ZSM-5 Catalyst for Selective Catalytic Reduction of NO by NH<sub>3</sub>
Houda Jouini,
Alessandra de Marcos-Galán,
Imène Mejri,
Rahma Bensouilah,
Mourad Mhamdi,
Teresa Blasco,
Gérard Delahay
Affiliations
Houda Jouini
LR01ES08 Laboratoire de Chimie des Matériaux et Catalyse, Faculté des Sciences de Tunis, Université de Tunis El Manar, Tunis 2092, Tunisia
Alessandra de Marcos-Galán
Instituto de Tecnología Química, Universitat Politècnica de València—Consejo Superior de Investigaciones Científicas (UPV-CSIC), Avda. de los Naranjos s/n, 46022 Valencia, Spain
Imène Mejri
LR01ES08 Laboratoire de Chimie des Matériaux et Catalyse, Faculté des Sciences de Tunis, Université de Tunis El Manar, Tunis 2092, Tunisia
Rahma Bensouilah
LR01ES08 Laboratoire de Chimie des Matériaux et Catalyse, Faculté des Sciences de Tunis, Université de Tunis El Manar, Tunis 2092, Tunisia
Mourad Mhamdi
LR01ES08 Laboratoire de Chimie des Matériaux et Catalyse, Faculté des Sciences de Tunis, Université de Tunis El Manar, Tunis 2092, Tunisia
Teresa Blasco
Instituto de Tecnología Química, Universitat Politècnica de València—Consejo Superior de Investigaciones Científicas (UPV-CSIC), Avda. de los Naranjos s/n, 46022 Valencia, Spain
Gérard Delahay
Institut Charles Gerhardt Montpellier (ICGM), Université de Montpellier, CNRS, ENSCM, 34293 Montpellier, France
A WO3/Fe-Cu-ZSM-5 catalyst was prepared using the solid state ion exchange method (SSIE) and its performance for the Selective Catalytic Reduction of NO with NH3 (NH3-SCR of NO) was investigated. The study shows that the tungsten addition can slightly improve the high temperature catalytic activity of Fe-Cu-ZSM-5. The influence of hydrothermal aging at 850 °C for 5 h on the structural and textural properties of WO3/Fe-Cu-ZSM-5 was also studied in this paper. The XRD and FE-SEM measurements did not indicate a breakdown of the zeolite structure upon steam treatment for both aged catalysts. The aged W-base catalyst demonstrates a lower deactivation and better catalytic activity for NO reduction than the bimetallic catalyst after hydrothermal aging despite the lower acidic properties as shown by FTIR-Pyr spectroscopy owing to the presence of tungsten oxide crystallites. The “severe” stage of aging occurring in the absence of W led to the formation of copper oxide agglomerates detected using STEM and H2-TPR techniques being responsible for the deterioration of SCR activity of the aged Fe-Cu-ZSM-5.
