RAIRS studies of CO adsorption on Pd/CeO2-x(111)/Pt(111)

Reflection absorption infrared spectroscopy (RAIRS) has been used to investigate the adsorption of CO on CeO2-x-supported Pd nanoparticles at room temperature. The results show that when CeO2-x is initially grown on Pt(I 11), a small proportion of the surface remains as bare Pt sites. However, when Pd is deposited onto CeO2-x/Pt(I 11), most of the Pd grows directly on top of the CeO2-x(111). RAIR spectra of CO adsorption on I ML Pd/CeO2-x/Pt(I 11) show a broad CO-Pd band, which is inconsistent with a single crystal Pd surface. However, the 5 ML and 10 ML Pd/CeO2-x/Pt(I 11) spectra show vibrational bands consistent with the presence of Pd(I 11) and (100) faces, suggesting the growth of Pd nanostructures with well defined facets. (c) 2006 Elsevier B.V. All rights reserved.