Characterization of Nb-Containing MnOx−CeO2 Catalyst for Low-Temperature Selective Catalytic Reduction of NO with NH3

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• 作者：Maria Casapu ; Oliver Krcher ; Max Mehring ; Maarten Nachtegaal ; Camelia Borca ; Messaoud Harfouche ; Daniel Grolimund
• 刊名：Journal of Physical Chemistry C
• 出版年：2010
• 出版时间：June 3, 2010
• 年：2010
• 卷：114
• 期：21
• 页码：9791-9801
• 全文大小：645K
• 年卷期：v.114,no.21(June 3, 2010)
• ISSN：1932-7455

文摘

The reactivity in the selective catalytic reduction of the individual and binary components of NbO_x−MnO_x−CeO₂ catalysts has been studied with coated cordierite monoliths in the temperature range of 150−450 °C. FTIRS, DRIFTS, TA, XRD, BET, and XAS have been used to elucidate the structural and catalytic properties. The results confirmed the contribution of the manganese oxides, particularly to the low-temperature NO-to-NO₂ oxidation reaction. The significant increase of the surface acidity as a result of niobium oxide addition has been established. The data obtained revealed also the strong interaction between the manganese and niobium catalytic active sites. This phenomenon leads to a very good distribution of the oxidizing and acidic sites in the catalyst structure and also diminishes the unselective NH₃ oxidation at higher temperatures. However, in order to keep the low-temperature catalytic activity, an excess of manganese relative to the niobium content is needed.