Negative Charging of Au Nanoparticles during Methanol Synthesis from CO2 /H2 on a Au/ZnO Catalyst: Insights from Operando IR and Near-Ambient-Pressure XPS and XAS Measurements.
Ali Mohamed Abdel-MageedAlexander KlyushinAzita RezvaniAxel Knop-GerickeRobert SchlöglRolf Jürgen BehmPublished in: Angewandte Chemie (International ed. in English) (2019)
The electronic and structural properties of Au/ZnO under industrial and idealized methanol synthesis conditions have been investigated. This was achieved by kinetic measurements in combination with time-resolved operando infrared (DRIFTS) as well as in situ near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) and X-ray absorption near-edge spectroscopy (XANES) measurements at the O K-edge together with high-resolution electron microscopy. The adsorption of CO during the reaction revealed the presence of negatively charged Au nanoparticles/Au sites during the initial phase of the reaction. Near-ambient-pressure XPS and XANES demonstrate the build-up of O vacancies during the reaction, which goes along with a substantial increase in the rate of methanol formation. The results are discussed in comparison with previous findings for Cu/ZnO and Au/ZnO catalysts.
Keyphrases
- reduced graphene oxide
- high resolution
- visible light
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- gold nanoparticles
- quantum dots
- air pollution
- electron microscopy
- room temperature
- particulate matter
- carbon dioxide
- single molecule
- mass spectrometry
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- computed tomography
- wastewater treatment
- dual energy
- solid state
- aqueous solution