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O: Fachverband Oberflächenphysik

O 36: Posters: Bio/organic Molecules on Surfaces, Graphene, Solid/liquid interfaces, Metal Substrates, Electronic Structure Theory

O 36.75: Poster

Dienstag, 1. April 2014, 18:30–22:00, P1

Electrocatalytic activity and stability of Pt nanoparticles on Ru(0001) supported graphene — •Jens Klein, Albert K. Engstfeld, Sylvain Brimaud, and R. Jürgen Behm — Ulm University, Institute of Surface Chemistry and Catalysis, D-89069 Ulm, Germany

Pt-based catalysts consisting of carbon supported Pt nanoparticles are widely used, e.g. in fuel cell technology, and it is well known that the performance of these catalysts depends sensitively on the size, density, shape and stability of the Pt nanoparticles.

Here we present results of a model study on the activity and stability of small Pt nanoparticles with narrow size distributions and mean sizes between some 10 - 20 atoms and below 3nm, which were grown on Ru(0001)-supported graphene. The graphene monolayers were prepared under ultra high vacuum (UHV) by ethylene decomposition on Ru(0001) at 1050 K. Pt cluster/nanoparticle arrays with well known particle- and size-distributions were formed by physical vapor deposition of Pt and characterized by scanning tunneling microscopy (STM).[1] The electrodes were subsequently transferred to an electrochemical flow cell attached to the UHV system, to investigate their electrochemical properties and the electrocatalytic activity during CO oxidation. In a last step, the samples were transferred back to the UHV for STM characterization, to evaluate the stability of the particles and correlate the results from the electrochemical measurements with the change in particle sizes and distributions.

[1] Y.Han, A.K. Engstfeld, R.J. Behm, J.W. Evans, J. Chem. Phys. 138, 134703 (2013).