Surface optical reflectance combined with x-ray techniques during gas-surface interactions

Summary, in English

High energy surface x-ray diffraction (HESXRD), x-ray reflectivity (XRR), mass spectrometry (MS) and surface optical reflectance (SOR) have been combined to simultaneously obtain sub-second information on the surface structure and morphology from a Pd(100) model catalyst during in situ oxidation at elevated temperatures and pressures resulting in Pd bulk oxide formation. The results show a strong correlation between the HESXRD and SOR signal intensities during the experiment, enabling phase determination and a time-resolved thickness estimation of the oxide by HESXRD, complemented by XRR measurements. The experiments show a remarkable sensitivity of the SOR to changes in the surface phase and morphology, in particular to the initial stages of oxidation/reduction. The data imply that SOR can detect the formation of an ultrathin PdO surface oxide layer of only 2-3 Å thickness.

• Author: S. Albertin; J. Gustafson; J. Zhou; S. Pfaff; M. Shipilin; S. Blomberg; L. R. Merte; O. Gutowski; A. C. Dippel; J. Zetterberg; E. Lundgren; U. Hejral
• Department/s: Synchrotron Radiation Research; Combustion Physics; Division of Chemical Engineering; NanoLund: Centre for Nanoscience
• Publishing year: 2020
• Language: English
• Publication/Series: Journal of Physics D: Applied Physics
• Volume: 53
• Issue: 22
• Links: http://dx.doi.org/10.1088/1361-6463/ab77df
• Document type: Journal article
• Publisher: IOP Publishing
• Topic: Materials Chemistry; Condensed Matter Physics (including Material Physics, Nano Physics); Atom and Molecular Physics and Optics
• Keywords: high energy surface x-ray diffraction; oxidation; Pd(100); surface optical reflectance
• Status: Published
• Project: Combined techniques for studies of catalysis
• ISBN/ISSN/Other: ISSN: 0022-3727