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O: Fachverband Oberflächenphysik
O 67: Poster: Oxide, Insulator and Semiconductor Surfaces
O 67.2: Poster
Mittwoch, 20. März 2024, 18:00–20:00, Poster C
A structural study of CO ligation to Cu adsorbed on Fe3O4 (001) — •Fulden Eratam1, Benedikt Klein1,2, Lena Puntscher3, Matthew Stoodley1,2, Alexander Generalov4, Alexei Preobrajenski4, Tien-Lin Lee1, Gareth Parkinson3, and David A. Duncan1 — 1Diamond Light Source, Didcot, UK — 2University of Warwick, Coventry, UK — 3TU Wien, Vienna, Austria — 4MAX IV, Lund, Sweden
Single atom catalysis (SAC) utilizes atomically dispersed single species of metals to serve as isolated active sites on a support and offers a promising tool for maximizing catalytic activity, selectivity and stability. Iron oxides are a popular support for such catalysts (e.g. [Angew. Int. Ed. 132 (2020), 12968]), where X-ray absorption near edge spectroscopy (XANES) is typically used to identify the coordination state of the SAC. The (001) surface of single crystal magnetite (Fe3O4) has been shown to coordinate a high density of single metal atoms [Science 346 (2014), 1215]. We have previously demonstrated that CO coordination pulls these atoms out of the surface by 0.2 Å [J. Chem. Phys. 152 (2020), 051102]. The current work highlights the effect of one such CO distortion on the XANES data and presents Cu L-edge XANES of Cu single metal adatoms adsorbed on Fe3O4(001) before and after CO coordination. In the absence of CO, it is found that Cu adatoms produce a XANE spectrum very similar to that of Cu2O. Meanwhile, CO coordination is found to produce a significant enhancement in the intensity of a pre-edge feature, resolved at an energy range typical of CuO.
Keywords: Single Atom Catalysis; Metal Adsorbates; Iron Oxides; Coordination Structure; Surface Structure