Carbon–NSR catalyst interaction: Impact on catalyst structure and NOx storage efficiency Review Article

Authors: Jennifer Klein, Dongliang Wu, Valerie Tschamber, Ioana Fechete, Francois Garin

Abstract:
The impact of the presence of carbon on the structure of model NO_x storage catalysts (NSR) and their ability to store NO_x were investigated. Three catalysts, composed of Pt and/or Ba supported on Al₂O₃, were prepared. Reactivity of the catalysts toward NO_x storage was studied during adsorption/TPD cycles. Comparison of the results obtained in the presence and absence of carbon in the catalytic bed revealed that a carbon–catalyst contact leads to a decrease in NO_x storage capacity attributed to a destabilization of nitrate species formed far from Pt sites. Both Al and Ba sites are affected. During the carbon oxidation process, an aging of the catalysts, caused by Pt sintering and Ba agglomeration, as observed using TEM technology. These structural modifications reduce the proximity between the Pt sites and adsorption sites (Ba and/or Al), which results in a decrease in the NO_x storage toward the ‘nitrite route’. 

Keywords:
NO_x storage capacity
Soot
Sintering
Platinum based catalyst
Barium nitrate

Published in: Applied Catalysis B: Environmental (Volumes 132–133, Pages 1-552, 27 March 2013)

Publisher: Elsevier  

ISSN Information: 0926-3373

Carbon–NSR catalyst interaction: Impact on catalyst structure and NOx storage efficiency Review Article

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