Photoemission Spectroscopy Study of Cu/CeO2 Systems: Cu/CeO2 Nanosized Catalyst and CeO2(111)/Cu(111) Inverse Model Catalyst

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• 作者：Vladimí ; r Matolí ; n ; Libor Sedl&aacute ; //pubs.acs.org/images/entities/ccaron.gif" border="0">ek ; Iva Matolí ; nov&aacute ; Franti//pubs.acs.org/images/enti
• 刊名：Journal of Physical Chemistry C
• 出版年：2008
• 出版时间：March 13, 2008
• 年：2008
• 卷：112
• 期：10
• 页码：3751 - 3758
• 全文大小：447K
• 年卷期：v.112,no.10(March 13, 2008)
• ISSN：1932-7455

文摘

Cerium oxide films equivalent to 2 ML of CeO₂ were grown at 520 K in an oxygen atmosphere on a cleanCu(111) substrate in order to prepare a model catalytic system. This "inverse model catalyst" was characterizedby low-energy electron diffraction (LEED), X-ray photoelectron spectroscopy (XPS) of core levels, and resonantphotoelectron spectroscopy (RPES) of the valence band. Samples annealed at 770 K exhibited a LEED patterncorresponding to the (1.5 × 1.5) CeO₂(111)/Cu(111) structure that can be interpreted as formation of a flat,well-ordered cerium oxide overlayer aligned with the principal crystallographic axes of the substrate. Themodel catalytic system corresponds well to a copper-loaded ceria nanopowder catalyst that exhibits growthof Cu(111) film structure on CeO₂(111) planes. Lowering of the CO oxidation temperature due to the Culoading is explained by CO adsorption on copper in the vicinity of highly active ceria planes providing oxygenfor the reaction.