Preparation of Rhodium/CexPr1-xO2 Catalysts: A Nanostructural and Nanoanalytical Investigation of Surface Modifications

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• 作者：Marí ; a P. Rodrí ; guez-Luque ; Juan C. Hern&aacute ; ndez ; Marí ; a P. Yeste ; Serafin Bernal ; Miguel A. Cauqui ; José ; M. Pintado ; José ; A. Pé ; rez-Omil ; Odile Sté ; pha
• 刊名：Journal of Physical Chemistry C
• 出版年：2008
• 出版时间：April 17, 2008
• 年：2008
• 卷：112
• 期：15
• 页码：5900 - 5910
• 全文大小：728K
• 年卷期：v.112,no.15(April 17, 2008)
• ISSN：1932-7455

文摘

By using a combination of transmission electron microscopy (TEM) and scanning transmission electronmicroscopy (STEM) techniques, we have followed in detail the structural and chemical changes occurring onthe very surface layers of powder Ce_xPr_1-xO₂ mixed oxides, used as supports, during the preparation of rhodium-supported catalyst by wet impregnation techniques. Results demonstrate the occurrence of Pr³⁺ leaching outof the Ce-Pr solid solution during the impregnation step, which promotes a severe spatial redistribution oflanthanide cations at the surface of the mixed oxide. A highly heterogeneous surface composition is reachedafter the metal deposition. Mobilization of the support also affects the features of the final surface structureof the metal-supported nanoparticles, which become decorated by patches of support material. All these factsseem crucial to properly understand the redox and catalytic behavior of this kind of materials.