Adsorption Sites and Ligand Effect for CO on an Alloy Surface: A Direct View

Y. Gauthier; M. Schmid; S. Padovani; E. Lundgren; V. Buš; G. Kresse; J. Redinger; P. Varga

doi:10.1103/PhysRevLett.87.036103

Adsorption Sites and Ligand Effect for CO on an Alloy Surface: A Direct View

Y. Gauthier, M. Schmid, S. Padovani, E. Lundgren, V. Buš, G. Kresse, J. Redinger, and P. Varga

Phys. Rev. Lett. 87, 036103 – Published 28 June 2001

Abstract

CO adsorption on a PtCo(111) surface was studied by scanning tunneling microscopy. Comparison of images with chemical contrast of Pt and Co and images showing the CO molecules indicates that CO resides exclusively on top of Pt sites and never on Co. CO bonding is highly sensitive to the chemical environment. The probability to find CO on a Pt atom increases drastically with the number of its Co nearest neighbors. Ab initio calculations show that this ligand effect is due to different positions of the center of the Pt $d$ band.

Received 15 January 2001

DOI:https://doi.org/10.1103/PhysRevLett.87.036103

Authors & Affiliations

Y. Gauthier¹, M. Schmid^2,*, S. Padovani¹, E. Lundgren^2,†, V. Buš³, G. Kresse⁴, J. Redinger⁵, and P. Varga²

¹Laboratoire de Cristallographie, CNRS, BP 166 X, F-38042 Grenoble Cedex 09, France
²Institut für Allgemeine Physik, Technische Universität Wien, A-1040 Wien, Austria
³Institute of Physical Engineering, Brno University of Technology, CZ-61669 Brno, Czech Republic
⁴Institut für Materialphysik, Universität Wien, Sensengasse 8, A-1090 Wien, Austria
⁵Center for Computational Materials Science, E158, Technische Universität Wien, A-1060 Wien, Austria

^*Corresponding author. Email address: schmid@iap.tuwien.ac.at
^†Present address: Department of Synchrotron Radiation Research, Institute of Physics, Lund University, Lund, Sweden.