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The influence of nonstoichiometry on LaMnO3 perovskite for catalytic NO oxidation

Paper ID Volume ID Publish Year Pages File Format Full-Text
45789 46422 2013 7 PDF Available
Title
The influence of nonstoichiometry on LaMnO3 perovskite for catalytic NO oxidation
Abstract

A series of structural modified LaxMnO3 (x = 0.9, 0.95, 1, 1.05, 1.11) perovskites used for NO oxidation was synthesized by a sol–gel method and characterized by XRD, BET, XPS, EPR and H2-TPR. La0.9MnO3 sample exhibits superior activity, and a 50% NO conversion at 250 °C is obtained. XPS and EPR results reveal a higher Mn4+/Mn3+ ratio in Mn-rich samples, which induce more active oxygen bonding to Mn4+ due to the need for balancing the chemical states and stabilizing the structure. Easily regenerated oxygen associated with Mn4+ catalyzes the low-temperature NO oxidation. The constant activation energy (44.8 kJ/mol) obtained in the kinetics tests indicates the same mechanism of NO oxidation operated on all the samples.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The LaxMnO3 (x = 0.9, 0.95, 1, 1.05, 1.11) perovskites are applied as catalysts for NO oxidation to NO2. ► Phase transition of crystal system appears by nonstoichiometry in LaMnO3. ► The Mn4+ content increases with lower La/Mn ratio (x value). ► The same mechanism of NO oxidation over the La-Mn-O perovskites is observed. ► The oxygen species associated with modified Mn4+/Mn3+ sites of the La-Mn-O perovskites catalyzes the low temperature NO oxidation.

Keywords
NO oxidation; Mn4+/Mn3+ ratio; Nonstoichiometry; LaMnO3 perovskite
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The influence of nonstoichiometry on LaMnO3 perovskite for catalytic NO oxidation
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Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis B: Environmental - Volumes 134–135, 2 May 2013, Pages 251–257
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us