CO Adsorption on Gold Clusters Stabilized on Ceria-Titania Mixed Oxides: Comparison with Reference Catalysts

详细信息    查看全文

• 作者：Floriana Vindigni ; Maela Manzoli ; Anna Chiorino ; Tatyana Tabakova ; Flora Boccuzzi
• 刊名：Journal of Physical Chemistry B
• 出版年：2006
• 出版时间：November 23, 2006
• 年：2006
• 卷：110
• 期：46
• 页码：23329 - 23336
• 全文大小：579K
• 年卷期：v.110,no.46(November 23, 2006)
• ISSN：1520-5207

文摘

Fourier transform infrared spectra of CO adsorption from 120 K up to room temperature on two gold catalystssupported on different mixed ceria-titania oxides are discussed in comparison with those obtained on Au/TiO₂ and Au/Fe₂O₃ reference catalysts provided by the World Gold Council. The spectra of adsorbed CO,run on the different samples before preliminary treatment, are shown and compared with those of the untreatedcatalysts and of the samples reduced either in CO or in hydrogen. Big differences have been found betweenthe ceria-titania supported samples and the reference ones: unusual absorption bands, irreversible to outgassing,have been detected after CO interaction on the untreated and oxidized ceria containing samples. Theseabsorptions are assigned to CO on Au_n⁺ small clusters stabilized at the ceria defects. By reduction in hydrogen,negatively charged Au_n^- species are produced on the same sample. Oxidized small particles are present onthe reference catalysts, but only on the untreated samples; after treatment, only metallic step sites are evident.