Effect of Phase Structure of MnO2 Nanorod Catalyst on the Activity for CO Oxidation

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• 作者：Shuhui Liang ; Fei Teng ; G. Bulgan ; Ruilong Zong ; Yongfa Zhu
• 刊名：Journal of Physical Chemistry C
• 出版年：2008
• 出版时间：April 10, 2008
• 年：2008
• 卷：112
• 期：14
• 页码：5307 - 5315
• 全文大小：291K
• 年卷期：v.112,no.14(April 10, 2008)
• ISSN：1932-7455

文摘

The mages/gifchars/alpha.gif" BORDER=0>-, mages/gifchars/beta2.gif" BORDER=0 ALIGN="middle">-, mages/gifchars/gamma.gif" BORDER=0 >-, and mages/gifchars/delta.gif" BORDER=0 >-MnO₂ nanorods were synthesized by the hydrothermal method. Their catalytic propertiesfor CO oxidation were evaluated, and the effects of phase structures on the activities of the MnO₂ nanorodswere investigated. The activities of the catalysts decreased in the order of mages/gifchars/alpha.gif" BORDER=0>- mages/entities/ap.gif"> mages/gifchars/delta.gif" BORDER=0 >- > mages/gifchars/gamma.gif" BORDER=0 >- > mages/gifchars/beta2.gif" BORDER=0 ALIGN="middle">-MnO₂. Themechanism of CO oxidation over the MnO₂ nanorods was suggested as follows. The adsorbed CO was oxidizedby the lattice oxygen, and the MnO₂ nanorods were partly reduced to Mn₂O₃ and Mn₃O₄. Then, Mn₂O₃ andMn₃O₄ were oxidized to MnO₂ by gaseous oxygen. CO chemisorption, the Mn-O bond strength of the MnO₂,and the transformation of intermediate oxides Mn₂O₃ and Mn₃O₄ into MnO₂ can significantly influence theactivity of the MnO₂ nanorods. The activity for CO oxidation was mainly predominated by the crystal phaseand channel structure of the MnO₂ nanorods.