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CO2 hydrogenation is a kinetically limited reaction, occurring exclusively at the catalyst surface. To achieve satisfactory catalytic conversions, it is essential to form a reactive interface that facilitates the adsorption of CO2 and its subsequent conversion to the desired products, i.e., methanol. The industrially established system for methanol production via CO2 hydrogenation is Cu/ZnO, however, the nature of the active surface is not fully discovered.1,2 Better understanding of the active phase and its deactivation mechanism might be achieved with the Catlab Laterally Condensed Catalyst approach. As CO2 hydrogenation catalysts, two types of model systems were utilized – Laterally Condensed Catalyst (LCC)3 with composition of 3 nm ZnO – 20 nm Cu – Si wafer (100), and Cu2O/ZnO nanocubes with varying Cu/Zn ratios4. In-situ microscopy and spectroscopy measurements such as in situTEM, ESEM, XPS, and XAS were performed to study the microscopic changes and the electronic structure as well as correlate these with the catalytic performance. During the in-situ performed XPS/XAS measurements, the ZnO overlayer acted as a protective layer for Cu against oxidation in the 3 nm ZnO-20 nm Cu LCC structure where Cu remained metallic throughout the reaction (CO2+H2 mixture), performed up to 220 °C. It was observed, comparing TEM images for both types of studied systems, that powder Cu2O/ZnO nanocubes represent an optimal reference for the LCC catalyst, due to their well-defined structure and morphology. In methanol synthesis conditions, ZnO initially segregates and forms a shell around the Cu2O nanocubes4. This shell delays the onset of reduction which helps preserve the cubic morphology.
- A. Beck et al., Chemical Reviews, 2024, 124, 8, 4543;
- T. Lunkenbein et al., Angew. Chem. Int. Ed., 2016, 55, 12708.
- Z. Li, Nat. Comm. submitted
- D. Kordus et al., J. Am. Chem. Soc. 2024, 146, 8677−8687
