Regensburg 2019 – wissenschaftliches Programm
O 37.10: Vortrag
Dienstag, 2. April 2019, 16:15–16:30, H16
Reduction and reoxidation of (111) and (100) oriented cerium oxide islands on Cu(111) — •Linus Pleines1, Francesca Genuzio2, Tevfik Onur Menteş2, Andrea Locatelli2, Jens Falta1,3, and Jan Ingo Flege4 — 1Institute of Solid State Physics, University of Bremen, Germany — 2ELLETRA Synchrotron Light Source, Basovizza, Italy — 3MAPEX Center for Materials and Processes, Bremen, Germany — 4Applied Physics and Semiconductor Spectroscopy, Brandenburg University of Technology Cottbus-Senftenberg, Germany
The conversion of CO2 to methanol is an important process of high industrial potential. It could help solving the greenhouse gas problem (CO2) and further provide methanol which can be used as a synthetic fuel. In order to lower the activation energy barrier of the reactions a catalyst is necessary. We studied the interaction of H2 and CO2 with ultrathin cerium oxide islands on a Cu(111) substrate observed by low-energy electron mircoscopy (LEEM), x-ray absorption spectroscopy (XAS) and resonant photoelectron spectroscopy (RPES). From earlier studies the orientation of the CeOx is known to be decisive for the catalytic activity. In our experiments CeOx(100) is directly compared to CeOx(111) via a side-by-side growth, so that the same conditions prevail during the experiment. At low temperatures no reduction of the CeOx(111) and CeOx(100) were observed. However, at a higher temperature the reduction was activated. Furthermore, we show that the exposure to CO2 leads to the formation of partially reoxidized CeOx and saturation below CeO2 with progressive CO2 exposure.