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. Issue 30 (18th June 2019)

• Record Type: Journal Article
• Authors: Abdel‐Mageed, Ali M.; Klyushin, Alexander; Rezvani, Azita; Knop‐Gericke, Axel; Schlögl, Robert; Behm, R. Jürgen
• Is Part Of: Angewandte Chemie international edition. Volume 58:Issue 30(2019)
• Page Start: 10325
• Page End: 10329
• Publication Date: 2019-06-18
• Subjects: Au/ZnO catalyst -- homogeneous catalysis -- in situ XPS/XANES -- methanol synthesis -- operando FTIR; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201900150
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: 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. Abstract : Put in charge : Methanol synthesis activity has been demonstrated to coincide with the formation of O vacancies during the initial activation period. These vacancies result in a negative charging of the Au nanoparticles during the reaction.