Platinum adsorption on ceria: A comparative theoretical study of different surfaces

Abstract A comparative study, based on the density functional theory, on the adsorption of single Pt atoms on the CeO2(111), (110), and (100) surfaces has been performed. According to the calculated adsorption energies, it is suggested that the deposited Pt atoms on the CeO2(111) surface are easy to aggregate and form nanoparticles compared with those on the CeO2(110) and (100) surfaces. Further, the interaction strength between Pt and the three CeO2 surfaces follows the order of (100) > (110) > (111). It is also found that there is a correlation between the formal oxidation state of the adsorbed Pt and its coordination number with respect to O. The Pt atom coordinated by one O atom on the CeO2 surfaces is only slightly charged and almost neutral, and that coordinately by four O atoms exclusively has the formal oxidation state of Pt2+. The possible reasons for these findings have been discussed. And the present theoretical results have been compared with the available experimental reports. It is expected that our studies will give useful insights into the shape-dependent interaction between Pt with CeO2 nanocrystals and the shape-dependent oxidation state of the deposited Pt.