Evidence for Electron-Hole Pair Excitation in the Associative Desorption of H2and D2from Au(111).
The dissociative adsorption reaction of hydrogen on noble metals is believed to be well-described within the Born-Oppenheimer approximation. In this work, we have experimentally derived translational energy distributions for selected quantum states of H2and D2formed in associative desorption reactions at a Au(111) surface. Using the principle of detailed balance, we compare our results to theory carried out at the same level of sophistication as was done for the reaction on copper. The theory predicts translational excitation that is much higher than is seen in experiment and fails to reproduce the experimentally observed isotope effect. The large deviations between experiment and theory are surprising because, for the same reactions occurring on Cu(111), a similar theoretical strategy agreed with experiment, yielding "chemical accuracy". We argue that electron-hole pair excitation is more important for the reaction on gold, an effect that may be related to the reaction's later transition state.
Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry , Am Faßberg 11, 37077 Göttingen, Germany.
Quan
http://orcid.org/0000-0001-8834-1229
Q
Shuai
Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry , Am Faßberg 11, 37077 Göttingen, Germany.|Institute for Physical Chemistry, Georg-August University of Goettingen , Tammannstraße 6, 37077 Göttingen, Germany.
Sven
S
Kaufmann
Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry , Am Faßberg 11, 37077 Göttingen, Germany.|Institute for Physical Chemistry, Georg-August University of Goettingen , Tammannstraße 6, 37077 Göttingen, Germany.
Daniel J
DJ
Auerbach
Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry , Am Faßberg 11, 37077 Göttingen, Germany.|Institute for Physical Chemistry, Georg-August University of Goettingen , Tammannstraße 6, 37077 Göttingen, Germany.
Dirk
D
Schwarzer
Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry , Am Faßberg 11, 37077 Göttingen, Germany.|Institute for Physical Chemistry, Georg-August University of Goettingen , Tammannstraße 6, 37077 Göttingen, Germany.|International Center for Advanced Studies of Energy Conversion, Georg-August University of Goettingen , Tammannstraße 6, 37077 Göttingen, Germany.
Alec M
AM
Wodtke