Using Auger transitions as a route to determine the oxidation state of copper in high-pressure electron spectroscopyShow others and affiliations
2024 (English)In: Surface Science, ISSN 0039-6028, E-ISSN 1879-2758, Vol. 749, article id 122565Article in journal (Refereed) Published
Abstract [en]
Accurate discrimination between metallic copper (Cu0) and cuprous oxide (Cu2O, Cu+) in electron spectroscopy commonly relies on the Auger electron spectroscopy (AES) Cu L3M4,5M4,5 transitions, as the X-ray photoelectron spectroscopy (XPS) Cu core-levels do not provide large enough binding energy shifts. The kinetic energy of the AES Cu L3M4,5M4,5 electrons is ∼917 eV, which leaves the AES electron susceptible for efficient scattering in the gas phase and attenuation of the signal above near-ambient pressure conditions. To study copper-based materials at higher pressures, e.g., the active state of a catalyst, Auger transitions providing electrons with higher kinetic energies are needed. This study focuses on AES transitions involving the Cu K-shell (1s electrons) that exhibit discernible kinetic energy shifts between the oxidation states of Cu. It is shown that the AES Cu KL2M4,5 transition, with kinetic energy of ∼7936 eV, provides a large enough kinetic energy shift between metallic copper and Cu2O. AES signal is demonstrated in an ambient of 150 mbar CO2.
Place, publisher, year, edition, pages
Elsevier BV , 2024. Vol. 749, article id 122565
Keywords [en]
Auger electron spectroscopy, Copper, Heterogeneous catalysis, High pressure XPS, Oxidation state
National Category
Condensed Matter Physics Atom and Molecular Physics and Optics
Identifiers
URN: urn:nbn:se:kth:diva-352343DOI: 10.1016/j.susc.2024.122565ISI: 001291801000001Scopus ID: 2-s2.0-85201426491OAI: oai:DiVA.org:kth-352343DiVA, id: diva2:1893050
Note
QC 20240905
2024-08-282024-08-282024-09-05Bibliographically approved