Dresden 2014 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 10: Solid-liquid Interfaces I

O 10.1: Vortrag

Montag, 31. März 2014, 10:30–10:45, WIL A317

On the stability of strained Cu overlayers on Pt(1 1 1), Au(1 1 1) and Au(1 0 0) electrodes under low potential conditions and in presence of CO and CO₂ — •Christian Schlaup and Sebastian Horch — Center for Individual Nanoparticle Functionality (CINF), Department of Physics, Technical University of Denmark (DTU), DK–2800 Kongens Lyngby, Denmark

Copper is known for its outstanding catalytic activity for the electroreduction of carbon dioxide. However, a tremendous overpotential in the order of 1 V needs to be overcome in order to drive this reaction. An approach to tune the reactivity of copper surfaces is to introduce strain into the surface, yielding in different binding situations of the involved reaction species.

A convenient experimental access to such strained copper surfaces is the electrodeposition of pseudomorphic films on electrodes with a bigger lattice constant. Yet, their stability under the desired reaction conditions is of crucial importance. By means of in-situ STM, the influence of CO₂ and the important reaction intermediate CO has been studied under low potential conditions. For the Pt(1 1 1) substrate, a CO induced restructuring, driven by attractive Pt-CO bindings was found. In contrast, Au-CO bindings are much less attractive, however, for Au(1 1 1) the stability of Cu films is limited by desorption of coadsorbed anions at low potentials. For Au(1 0 0) neither effect was found, instead an surface alloy forms under the desired reaction conditions.