Reversible formation of a PdCx phase in Pd nanoparticles upon CO and O-2 exposure

Summary, in English

The structure and chemical composition of Pd nanoparticles exposed to pure CO and mixtures of CO and O-2 at elevated temperatures have been studied in situ by a combination of X-ray Diffraction and X-ray Photoelectron Spectroscopy in pressures ranging from ultra high vacuum to 10 mbar and from room temperature to a few hundred degrees celsius. Our investigation shows that under CO exposure, above a certain temperature, carbon dissolves into the Pd particles forming a carbide phase. Upon exposure to CO and O-2 mixtures, the carbide phase forms and disappears reversibly, switching at the stoichiometric ratio for CO oxidation. This finding opens new scenarios for the understanding of catalytic oxidation of C-based molecules.

• Author: Olivier Balmes; Andrea Resta; Didier Wermeille; Roberto Felici; Maria Messing; Knut Deppert; Zhi Liu; Michael E. Grass; Hendrik Bluhm; Richard van Rijn; Joost W. M. Frenken; Rasmus Westerstroem; Sara Blomberg; Johan Gustafson; Jesper N Andersen; Edvin Lundgren
• Department/s: Solid State Physics; Synchrotron Radiation Research; NanoLund: Centre for Nanoscience
• Publishing year: 2012
• Language: English
• Pages: 4796-4801
• Publication/Series: Physical Chemistry Chemical Physics
• Volume: 14
• Issue: 14
• Links: http://dx.doi.org/10.1039/c2cp22873d
• Document type: Journal article
• Publisher: Royal Society of Chemistry
• Topic: Atom and Molecular Physics and Optics; Condensed Matter Physics (including Material Physics, Nano Physics)
• Status: Published
• ISBN/ISSN/Other: ISSN: 1463-9084