SKM 2023 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 39: Poster Session: Heterogeneous Catalysis and Surface Dynamics
O 39.4: Poster
Dienstag, 28. März 2023, 18:00–20:00, P2/EG
Operando sXRD study of copper-zinc-alumina (CZA) model systems under methanol synthesis conditions — •Erik Beck1,2, Vedran Vonk1,2, Heshmat Noei1,2, and Andreas Stierle1,2 — 1Centre for X-ray and Nano Science, Hamburg, Germany — 2German Electron Synchrotron DESY, Hamburg, Germany
Methanol synthesis from gas mixtures of H2, CO and CO2 is an important industrial process in which copper-zinc-alumina (CZA) has been identified as a high performing catalyst. Typically, the products and reactants are gases used at pressures of >30 bar and a temperature of 250-300 degree C. Because of the dynamic nature of the catalyst under such industrial conditions, the underlying mechanisms and reaction paths are still under debate, since the traditional surface science techniques cannot be used at such high pressures. In order to bridge this pressure gap and gather structural information of the system in real operando conditions, we designed a special experimental setup for synchrotron-based high pressure SXRD. By using dedicated Cu and Zn UHV MBE growth chambers, we were able to prepare epitaxial model systems of the CZA catalysts composed of epitaxial Cu nanoparticles on Al2O3 single crystal surfaces. We performed operando high energy x-ray diffraction experiments on such model catalysts at up to 30 bar and 300degC at the High Energy Materials Science Beamline at DESY and we were able to follow the structural changes of the Cu nanoparticles during oxidation and reduction in different gas compositions.