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Methanol oxidation on LaBO3 (B = Co, Mn, Fe) perovskite-type catalysts prepared by reactive grinding

Paper ID Volume ID Publish Year Pages File Format Full-Text
43256 45960 2008 10 PDF Available
Title
Methanol oxidation on LaBO3 (B = Co, Mn, Fe) perovskite-type catalysts prepared by reactive grinding
Abstract

Perovskite-type mixed oxides LaBO3 (with B = Co, Mn, Fe) with high specific surface area were prepared by reactive grinding. These catalysts were characterized by N2 adsorption, X-ray diffraction, H2 temperature-programmed reduction (TPR-H2), O2-, CH3OH- and CO2-temperature-programmed desorption (TPD). The catalytic performance of the samples for methanol oxidation was evaluated. The reaction rates were found to be strongly related to the amount of α-oxygen available and to the density of surface anion vacancies. A mechanism for total oxidation of methanol into CO2 was also proposed in which the amount of α-oxygen was an important parameter of the reaction rate. Indeed two kinds of reaction intermediates can be produced depending on the surface density of α-oxygen. Under an excess of α-oxygen the reaction intermediate was found to be a monodentate carbonate which decomposes into CO2. However, as soon as a lack of α-oxygen was observed in the structure, the dominant reaction intermediate was a bidentate carbonate which induces a consumption of anion vacancies in spite of the production of CO2. The differences observed between the three catalysts under study were discussed according to the observations of the characterization, the activity over methanol oxidation and the proposed mechanism.

Graphical abstractPerovskite-type mixed oxides LaBO3 (with B = Co, Mn, Fe) with high specific surface area were prepared by reactive grinding. The catalytic performance of the samples for methanol oxidation was evaluated. The reaction rates were found to be strongly related to the amount of α-oxygen available and to the density of surface anion vacancies. A mechanism for this oxidation was proposed.Figure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
Perovskite; Methanol oxidation; Thermodesorption experiments; Carbonates
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Methanol oxidation on LaBO3 (B = Co, Mn, Fe) perovskite-type catalysts prepared by reactive grinding
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Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 343, Issues 1–2, 1 July 2008, Pages 29–38
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
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Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
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Full-text PDF Download
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Any Questions? feel free to contact us