COMPARISON OF THE NATURE OF THE HYDROGEN-METAL BOND ON PD(111) AND NI(111) BY A PERIODIC DENSITY-FUNCTIONAL METHOD

Authors
Citation
Jf. Paul et P. Sautet, COMPARISON OF THE NATURE OF THE HYDROGEN-METAL BOND ON PD(111) AND NI(111) BY A PERIODIC DENSITY-FUNCTIONAL METHOD, Surface science, 356(1-3), 1996, pp. 403-409
Citations number
27
Categorie Soggetti
Chemistry Physical
Journal title
ISSN journal
00396028
Volume
356
Issue
1-3
Year of publication
1996
Pages
403 - 409
Database
ISI
SICI code
0039-6028(1996)356:1-3<403:COTNOT>2.0.ZU;2-H
Abstract
The adsorption of H on Pd(111) and Ni(111) has been studied with densi ty functional calculations, including GGA to compute the exchange and correlation energies. The surface is described by a two-dimensional sl ab with a periodic (1x1) adsorption of H atoms. Among the surface site s, the fee hollow site is found to be the most stable on Pd, while on nickel, the fee and hcp hollow sites give the same binding energies. T he adsorption energies corresponding to these sites are -0.27 eV and - 0.49 eV for Pd and Ni, respectively. The energy, as well as the geomet ry, are in good agreement with experimental data. This study focuses o n the electronic properties of the M-H bond in order to explain the di fferences that appear between the two metals. The existence of a split -off state is proven in the case of Pd, and rejected for Ni. A detaile d investigation of the DOS and COOP curves explains the nature of the most stable site. It pinpoints the respective roles played by the d an d sp bands in the adsorption phenomenon.