Restructuring of AuPd nanoparticles studied by a combined XAFS/DRIFTS approach

Gibson, E. K. et al. (2015) Restructuring of AuPd nanoparticles studied by a combined XAFS/DRIFTS approach. Chemistry of Materials, 27(10), pp. 3714-3720. (doi: 10.1021/acs.chemmater.5b00866)

Abstract

The use of AuPd nanoparticles in catalysis is widespread, with the activity being attributed to their precise structural properties. We demonstrate the restructuring of AuPd nanoparticles under CO oxidation conditions using a combined XAFS/DRIFTS approach. The fresh catalyst exhibits PdO islands at the surface of the nanoparticles, which are reduced under reaction conditions, a process observed via both DRIFTS and Pd K-edge XAFS measurements. From the EXAFS analysis alone the nanoparticles were observed to have a Au rich core with an outer region of intimately mixed Au and Pd atoms. This structure was found to remain mostly unaltered throughout reaction. However, the DRIFTS spectra showed that although Au was present on the surface during the initial stages of reaction the surface rearranged just before light-off, and contained only Pd atoms thereafter. This study highlights the advantage of this combined approach, where both the surface structure and local environment of the constituent metals can be probed simultaneously, allowing a complete picture of the restructuring of these bimetallic particles to be obtained under reaction conditions.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Gibson, Dr Emma
• Authors: Gibson, E. K., Beale, A. M., Catlow, C. R. A., Chutia, A., Gianolio, D., Gould, A., Kroner, A., Mohammed, K. M. H., Perdjon, M., Rogers, S. M., and Wells, P. P.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Chemistry of Materials
• Publisher: American Chemical Society
• ISSN: 0897-4756
• ISSN (Online): 1520-5002
• Published Online: 27 April 2015
• Copyright Holders: Copyright © 2015 American Chemical Society
• First Published: First published in Chemistry of Materials 27(10):3714-3720
• Publisher Policy: Reproduced under a Creative Commons License