Morphology Dependence of Catalytic Properties of Ni/CeO2 Nanostructures for Carbon Dioxide Reforming of Methane

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• 作者：Xianjun Du ; Dengsong Zhang ; Liyi Shi ; Ruihua Gao ; Jianping Zhang
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：May 10, 2012
• 年：2012
• 卷：116
• 期：18
• 页码：10009-10016
• 全文大小：483K
• 年卷期：v.116,no.18(May 10, 2012)
• ISSN：1932-7455

文摘

The comparative catalytic activity and coke resistance are examined in carbon dioxide reforming of methane over Ni/CeO₂ nanorods (NR) and nanopolyhedra (NP). The Ni/CeO₂鈥揘R catalysts display more excellent catalytic activity and higher coke resistance compared with the Ni/CeO₂鈥揘P. The high resolution transmission electron microscope reveals that the predominantly exposed planes are the unusually reactive {110} and {100} planes on the CeO₂鈥揘R rather than the stable {111} one on the CeO₂鈥揘P. The prepared samples were also characterized by X-ray diffraction, transmission electron microscopy, hydrogen temperature-programmed reduction, X-ray photoelectron spectroscopy, UV and visible Raman spectra, and oxygen temperature-programmed oxidation. The {110} and {100} planes show great superiority for the anchoring of Ni nanoparticles, which results in the existence of strong metal鈥搒upport interaction effect (SMSI). The SMSI effect can be helpful to prevent sintering of Ni particles, which benefits to reduce the deactivation of catalytic activity. Besides, the oxygen vacancies and the mobility of lattice oxygen also show the morphology dependence. They can participate into the catalytic reaction and be beneficial to the activation of carbon deposition. In conclusion, the excellent catalytic activity and coke resistance of the Ni/CeO₂鈥揘R should be attributed to the SMSI effect and abundant oxygen vacancies.