Dresden 2011 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 20: Solid / liquid interfaces II
O 20.8: Vortrag
Montag, 14. März 2011, 19:00–19:15, WIL B321
Stability and electrocatalytic activity of Pt nanoclusters supported on graphene monolayers on Ru(0001) — •Otavio B. Alves1, Christoph Lorenz1, Harry E. Hoster1,2, and R. Jürgen Behm1 — 1Ulm University, Institute of Surface Chemistry and Catalysis, 89069 Ulm, Germany — 2Present Address: Technische Universität München, Centre for Electromobility, 50 Nanyang Drive, Singapore 637553
We have investigated the electrochemical properties and the electrocatalytic activity of model electrodes consisting of nanosized Pt clusters (10 - 50 atoms) on a graphene monolayer film deposited on a Ru(0001) substrate. The graphene films are attractive supports since they provide a structurally well-defined nanostructured template for the formation of ordered arrays of metal nanoparticles or clusters [1]. Inasmuch as the graphene covered surface is electrochemically inert, these model systems allow us to determine the electrochemical characteristics and the electrocatalytic activity of the Pt clusters. Activity and stability of theses systems are measured in a wall-jet type flow cell located in an electrochemical pre-chamber attached to the main UHV system. Cluster arrays with different total Pt coverages and cluster size distributions, as determined by scanning tunnelling microscopy (STM), were investigated, concentrating on the O2 reduction reaction as model reaction. The general electrochemical behaviour of the Pt cluster arrays will be discussed and compared to that of bulk Pt.
A. T. N’Diaye et al.; Phys. Rev. Lett. 1997, 97, 215501.