Inelastic electron scattering by the gas phase in near ambient pressure XPS measurements

Pielsticker, Lukas; Nicholls, Rachel; Beeg, Sebastian; Hartwig, Caroline; Klihm, Gudrun; Schlögl, Robert; Tougaard, S.; Greiner, Mark

doi:10.1002/sia.6947

Cited by 8 publications

(1 citation statement)

References 47 publications

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“…Ambient pressure XPS Cu 2p spectra of Cu/O-bZnO and Cu/vZnO at 500 K in 200 mbar of H 2 or CO 2 , respectively. The maxima at 933.5 and 953.3 eV relate to Cu 2p 3/2 and 2p 1/2 of CuO, whereas the shoulders at 933.0 and 952.8 eV are the respective features for Cu or Cu 2 O. Asterisks point out features that are due to inelastic scattering with the gas phase . Spectra were translated vertically.…”

Section: Resultsmentioning

confidence: 99%

Role of Oxidation–Reduction Dynamics in the Application of Cu/ZnO-Based Catalysts

Gleißner

Chung

Semione

et al. 2023

ACS Appl. Nano Mater.

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We investigated Cu nanoparticles (NPs) on vicinal and basal ZnO supports to obtain an atomistic picture of the catalyst’s structure under in situ oxidizing and reducing conditions. The Cu/ZnO model catalysts were investigated at elevated gas pressures by high energy grazing incidence X-ray diffraction and ambient pressure X-ray photoelectron spectroscopy (AP-XPS). We find that the Cu nanoparticles are fully oxidized to Cu2O under atmospheric conditions at room temperature. As the nanoparticles swell during oxidation, they maintain their epitaxy on basal ZnO (000 ± 1) surfaces, whereas on the vicinal ZnO (101̅4) surface, the nanoparticles undergo a coherent tilt. We find that the oxidation process is fully reversible under H2 flow at 500 K, resulting in predominantly well-aligned nanoparticles on the basal surfaces, whereas the orientation of Cu NPs on vicinal ZnO was only partially restored. The analysis of the substrate crystal truncation rods evidences the stability of basal ZnO surfaces under all gas conditions. No Cu–Zn bulk alloy formation is observed. Under CO2 flow, no diffraction signal from the nanoparticles is detected, pointing to their completely disordered state. The AP-XPS results are in line with the formation of CuO. Scanning electron microscopy images show that massive mass transport has set in, leading to the formation of larger agglomerates.

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Section: Resultsmentioning

confidence: 99%