Nanoporous Platinum Doped Cerium Oxides Thin Films Grown on Silicon Substrates: Ionic Platinum Localization and Stability. Issue 4 (22nd December 2016)

• Record Type: Journal Article
• Authors: Simon, Pardis; Zanfoni, Nicolas; Avril, Ludovic; Li, Zheshen; Potin, Valérie; Domenichini, Bruno; Bourgeois, Sylvie
• Is Part Of: Advanced materials interfaces. Volume 4:Issue 4(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2016-12-22
• Subjects: chemical vapor deposition -- platinum‐doped cerium oxide thin films -- transmission electron microscopy -- X‐ray photoelectron spectroscopy; Materials science -- Periodicals; 620.11
• DOI: 10.1002/admi.201600821
• Languages: English
• ISSNs: 2196-7350

Abstract

Abstract : In this study, the characterization of nanostructured Pt‐doped CeO2 films with low platinum content and porous structure is reported, deposited on silicon substrate by direct liquid injection chemical vapor deposition. The platinum localization and concentration in the nanocomposite are determined by scanning transmission electron microscopy associated with energy dispersive X‐ray spectroscopy. Films are made of ≈3 nm diameter CeO2 particles and platinum is homogeneously dispersed through the layers. X‐ray photoelectron spectroscopy (XPS) also shows that platinum is mainly in an ionic Pt 2+ state. After diffusion through the preformed porous structure of ceria films, the platinum precursor decomposes at the surface of each ceria particle forming the films, producing a homogeneous platinum‐doped CeO2 nanocomposite. This result is supported by synchrotron radiation XPS experiment, where the measured relative Pt concentration demonstrates that platinum is decomposed only at the surface of ceria particles. Finally, when the saturation of Pt 2+ sites at the surface of ceria particles is reached, metallic nanoclusters are formed from platinum excess. Abstract : A growth model is proposed for the formation of porous Pt‐doped CeO2 thin films synthetized by direct liquid injection‐chemical vapor deposition on Si substrate. A homogeneous Pt‐doped CeO2 nanocomposite with low platinum loading is evidenced, while adequate nanofacets at the CeO2 particles' surface induces Pt 2+ formation localized at the CeO2 surface. Such low Pt‐content porous structures are promising as efficient anode catalysts in fuel cells.