Structure of the Metal–Support Interface and Oxidation State of Gold Nanoparticles Supported on Ceria
- Autori: Longo, A; Liotta, LF; Pantaleo, G; Giannici, F; Venezia, AM; Martorana, A
- Anno di pubblicazione: 2012
- Tipologia: Articolo in rivista (Articolo in rivista)
- Parole Chiave: EXAFS, ceria, catalysis, gold
- OA Link: http://hdl.handle.net/10447/61764
Abstract
An Au/CeO2 model catalyst was prepared by deposition–precipitation, with the aim of obtaining a sample suitable for a detailed X-ray absorption fine structure (XAFS) analysis of the gold–ceria interface structure. The results demonstrate the existence of a large interface between the gold particle and the support oxide, characterized by well-defined Au–O and Au–Ce interactions extending up to 6.4 Å. The complex interface structure is retained after CO treatment up to 250 °C and subsequent reoxidation at 400 °C. The analysis of the XANES spectra, and the Au–O distance of 2.21 Å, longer than Au–O bond lengths previously reported for Au/ceria catalysts, suggest a low oxidation state for the gold atoms placed at the interface between Au and ceria.