Regensburg 2022 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 15: Solid-Liquid Interfaces 2: Structure and Spectroscopy

O 15.10: Vortrag

Montag, 5. September 2022, 17:30–17:45, S054

Structure dependent product selectivity of the CO electroreduction on Au(111) electrodes modified with Cu adatoms — •Daniel Winkler, Toni Moser, Christoph Griesser, Matthias Leitner, and Julia Kunze-Liebhäuser — University of Innsbruck, Innrain 52c, 6020 Innsbruck, Austria

The efficient conversion of carbon dioxide (CO₂) into valuable hydrocarbons could be a promising solution for storage of excess energy and carbon neutral transportation. The electrochemical reduction of CO₂ has been extensively studied on different monometallic surfaces, where Cu remains the only metal providing a sufficient formation activity to value-added products, such as methane or ethylene. Despite this beneficial behavior, further strategies to increase the product selectivity must be found. This can be accomplished by understanding the exact CO₂ reduction reaction (CO₂RR) mechanism, which remains one of the most challenging problems. Here we focus on the carbon monoxide (CO) reduction on Au(111) electrodes modified with different coverages of Cu adatoms to address this issue. Differential electrochemical mass spectrometry (DEMS) shows an increase in selectivity for the formation of ethylene at low Cu coverages. In situ electrochemical scanning tunneling microscopy (EC-STM) and X-ray photoelectron spectroscopy results suggest that two different neighboring CO adsorption sites present at the interface between the metallic Cu islands and the Au(111) surface, which is maximized at low coverages, provide ideal conditions for a facilitated CO-CO coupling reaction resulting in an enhanced formation of ethylene.