1. Strong Influence of Coadsorbate Interaction on CO Desorption Dynamics on Ru(0001) Probed by Ultrafast X-Ray Spectroscopy and Ab Initio Simulations
- Author
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Henrik Öberg, Georgi L. Dakovski, Giuseppe Mercurio, Jerry LaRue, William F. Schlotter, Jörgen Gladh, Martin Wolf, Hirohito Ogasawara, Lars G. M. Pettersson, Wilfried Wurth, Jens K. Nørskov, May Ling Ng, Hongliang Xin, Alexander Föhlisch, Jonas A. Sellberg, Joshua J. Turner, Michael P. Minitti, Sarp Kaya, Anders Nilsson, Martina Dell'Angela, Dennis Nordlund, Henrik Öström, Martin Beye, F. Hieke, Frank Abild-Pedersen, Kaya, Sarp (ORCID 0000-0002-2591-5843 & YÖK ID 116541), Xin, H, Larue, J, Oberg, H., Beye, M., Dell'Angela, M., Turner, J. J., Gladh, J., Ng, M. L., Sellberg, J. A., Mercurio, G., Hieke, F., Nordlund, D., Schlotter, W. F., Dakovski, G. L., Minitti, M. P., Fohlisch, A., Wolf, M., Wurth, W., Ogasawara, H., Norskov, J. K., Ostrom, H., Pettersson, L. G. M., Nilsson, A., Abild-Pedersen, E., College of Sciences, and Department of Chemistry
- Subjects
X-ray spectroscopy ,Materials science ,Valence (chemistry) ,Ab initio ,General Physics and Astronomy ,Charge density ,Institut für Physik und Astronomie ,Electronic structure ,Chemical physics ,Adsorbate interactions ,Emission-spectroscopy ,Laser ,Oxidation ,Electron ,Adsorption ,Metal ,Coadsorption ,Surfaces ,Oxygen ,Desorption ,Atom ,ddc:550 ,Inhouse research on structure dynamics and function of matter ,Atomic physics ,Potential of mean force ,Multidisciplinary physics ,photoemission - Abstract
We show that coadsorbed oxygen atoms have a dramatic influence on the CO desorption dynamics from Ru(0001). In contrast to the precursor-mediated desorption mechanism on Ru(0001), the presence of surface oxygen modifies the electronic structure of Ru atoms such that CO desorption occurs predominantly via the direct pathway. This phenomenon is directly observed in an ultrafast pump-probe experiment using a soft x-ray free-electron laser to monitor the dynamic evolution of the valence electronic structure of the surface species. This is supported with the potential of mean force along the CO desorption path obtained from density-functional theory calculations. Charge density distribution and frozen-orbital analysis suggest that the oxygen-induced reduction of the Pauli repulsion, and consequent increase of the dative interaction between the CO 5 sigma and the charged Ru atom, is the electronic origin of the distinct desorption dynamics. Ab initio molecular dynamics simulations of CO desorption from Ru(0001) and oxygen-coadsorbed Ru(0001) provide further insights into the surface bond-breaking process., US Department of Energy, Basic Energy Science; Swedish Research Council (VR); Department of Energy, Laboratory Directed Research and Development; VolkswagenStiftung; LCLS, Stanford University; Lawrence Berkeley National Laboratory (LBNL); University of Hamburg; Center for Free Electron Laser Science (CFEL)
- Published
- 2014
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