Dresden 2011 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 21: Thermodynamics and Statistical Physics of Small Systems (contributed talks)
DY 21.3: Vortrag
Mittwoch, 16. März 2011, 12:15–12:30, HÜL 186
Free gold clusters in CO and O2 atmosphere: an ab initio study. — •Elizabeth C. Beret, Luca M. Ghiringhelli, and Matthias Scheffler — Fritz-Haber-Institut der Max-Planck-Gesellschaft Berlin, Germany
The marked catalytic activity of gold nanoparticles
has inspired a large number of scientific contributions from
different fields.
However, many questions still lack a satisfying answer,
for example what are the structures and stoichiometries
of the gold particles in the presence
of the reactive gases,
and how do their catalytic properties depend on the particle size
[1].
We answer these questions for neutral gold clusters modeled in a
gas phase atmosphere
containing CO and O2 in variable compositions,
and in a temperature range between 100 and 600 K.
To this aim, DFT (PBE)–based
ab initio atomistic thermodynamics technique
[2] is applied,
including full account of the vibrational contribution to the
free energy.
As a result, the preferred cluster+adsorbate structures for
different environmental conditions
are obtained and
interpreted as candidate intermediates in the catalytic CO
oxidation reaction.
[1] R. Meyer, C. Lemire, S. K. Shaikhutdinov and H. J. Freund, Gold Bull. 2004, 37, 72–124. [2] K. Reuter and M. Scheffler, Phys. Rev. B 2001, 65, 035406; C. M. Weinert and M. Scheffler, Mat. Sci. Forum 1986, 10–12, 25–30; M. Scheffler and J. Dabrowski, Phil. Mag. A 1988, 58, 107–121.