TY - GEN A1 - Sanchez-Barquilla, Raquel A1 - Tschammer, Rudi A1 - Buß, Lars A1 - Morales, Carlos A1 - Flege, Jan Ingo T1 - The relation between substrate, Sm alloy, and surface sensitivity of ceria (111)- and (100)-oriented nano-islands on Ru(0001) and Cu(111) T2 - Verhandlungen der DPG N2 - Inverse oxide/metal catalysis allows achieving better catalytic performance than its traditional counterpart. For example, in cerium-based inverse catalyst systems, the Ce3+ states have been shown to be the active sites for methanol synthesis. This suggests that the activity can be enhanced by promoting those through alloying with trivalent, catalytically active rare-earth metals, as, e.g. Sm. We present low-energy and X-ray photoemission electron microscopy (LEEM/XPEEM), investigations that show how epitaxially grown (100)- and (111)-oriented CeO2 islands may be modified and/or alloyed by post-deposited metallic Sm. For the Ce1−xSmxO2−δ/Ru(0001) system, the CeO2 (111)-oriented islands undergo a structural change, concomitant with a partial conversion from Ce4+ to Ce3+. Surprisingly, for Ce1−xSmxO2−δ/Cu(111) the result is found to be face-dependent since only (100)-oriented CeOx islands were reduced whereas the (111)-oriented islands remained unaltered. Both systems have been exposed to reducing (H2) and oxidizing (CO2) conditions, resulting in higher reduction and in a complete recovery of the Ce4+ states, respectively. These unexpected results indicate a complex interaction not only between cerium and the doping element, but also an intricate interplay with the metallic substrate. KW - ceria KW - low-energy electron microscopy (LEEM) KW - X-ray photoemission electron microscopy (XPEEM) KW - samarium KW - metal substrate influence on reduction KW - orientation Y1 - 2024 UR - https://opus4.kobv.de/opus4-UBICO/frontdoor/index/index/docId/33135 UR - https://www.dpg-verhandlungen.de/year/2024/conference/berlin/part/o/session/85/contribution/6 SN - 0420-0195 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER -