Dresden 2026 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 13: Solid-liquid interfaces: Reactions and electrochemistry I

O 13.10: Vortrag

Montag, 9. März 2026, 17:15–17:30, TRE/PHYS

Facet-dependent restructuring and catalytic activity of Cu single crystals during CO electro-oxidation — Matthias Leitner, Francesc Valls Mascaro, •Andrea Auer, and Julia Kunze-Liebhäuser — Institute of Physical Chemistry, University of Innsbruck, Austria

Understanding how surface structure relates to catalytic activity is essential for designing efficient electrocatalysts. Copper (Cu) is known to restructure under reaction conditions, yet the precise impact of this dynamic behavior on activity remains largely unclear. Here, we combine electrochemistry with in situ electrochemical scanning tunneling microscopy (EC-STM) to investigate CO electro-oxidation on Cu(111) and Cu(100) single crystals and correlate activity with facet-specific structural changes. Both surfaces undergo nanometer-scale restructuring, forming undercoordinated Cu adatoms that act as active sites. Their evolution, however, differs significantly: Cu(111) shows dynamic, reversible restructuring that maintains a high density of adatom nanoclusters, whereas Cu(100) forms clusters that evolve less reversibly, with a gradual reduction in density. Interestingly, the evolution of clusters and their density does not directly correlate with the observed catalytic activity for either facet. Instead, we propose that the differences in activity stem primarily from variations in the effective density of the catalytically active Cu adatoms and their distinct interaction with reactants, rather than from different structural motifs. These results underscore the crucial role of dynamic restructuring in guiding the design of Cu-based electrocatalysts.

Keywords: electrochemical scanning tunneling microscopy; CO electro-oxidation; structure-activity relationship; surface restructuring; Cu single crystals