1. Using Auger transitions as a route to determine the oxidation state of copper in high-pressure electron spectroscopy
- Author
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Soldemo, Markus, Garcia-Martinez, Fernando, Goodwin, Christopher M., Lömker, Patrick, Shipilin, Mikhail, Nilsson, Anders, Amann, Peter, Kaya, Sarp, Weissenrieder, Jonas, Soldemo, Markus, Garcia-Martinez, Fernando, Goodwin, Christopher M., Lömker, Patrick, Shipilin, Mikhail, Nilsson, Anders, Amann, Peter, Kaya, Sarp, and Weissenrieder, Jonas
- Abstract
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., QC 20240905
- Published
- 2024
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