Dresden 2026 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 23: Catalysis and surface reactions – Poster
O 23.3: Poster
Monday, March 9, 2026, 18:00–20:00, P2
From model to powder systems: Sm-doped ceria for CO2 conversion. — •Raquel Sánchez-Barquilla1, Sichen Liu1, Alexander Contreras-Payares2, Pablo G. Lustemberg2, Dominic Guttmann1, Carlos Morales1, Fabian Rachow1, Verónica Ganduglia-Pirovano2, and Jan Ingo Flege1 — 1Brandenburg University of Technology, Cottbus-Senftenberg, Germany — 2Instituto de Catálisis y Petroleoquímica, Madrid, Spain
Reducible oxides are crucial in many heterogeneously catalyzed redox reactions because they can store and release oxygen during the catalytic cycle. Among these, cerium oxide (CeO2) stands out due to its facile transition between the Ce4+ and Ce3+ oxidation states. Furthermore, the Ce3+ cations have been suggested to provide the active sites for CO2 activation. Consequently, the catalytic performance of ceria-based catalysts may be significantly enhanced by promoting and stabilizing these sites, e. g., by alloying with trivalent rare-earth (RE) metals that also form cubic sesquioxides (RE2O3), such as samarium.
Here, we present a model system composed of (111)-oriented Sm-doped ceria nanoislands studied using X-ray photoelectron spectroscopy under near-ambient pressure. We show that Sm is crucial for CO2 activation. This activation is accompanied by a charge-transfer process that modifies the measured Ce3+/Ce4+ ratio, as explained by density functional theory calculations. Once the reaction mechanism was established, we performed operando absorption spectroscopy on powder catalysts with different Sm/Ce ratios to examine the effect of Sm doping under more realistic conditions.
Keywords: catalysis; samaria; ceria; NAP-XPS; XANES