Poisoning of Hydrogen Dissociation at Pd (100) by Adsorbed Sulfur Studied by ab initio Quantum Dynamics and ab initio Molecular Dynamics

Abstract

We report calculations of the dissociative adsorption of H_2 at Pd (100) covered with 1/4 monolayer of sulfur using quantum dynamics as well as molecular dynamics and taking all six degrees of freedom of the two H atoms fully into account. The ab initio potential-energy surface (PES) is found to be very strongly corrugated. In particular we discuss the influence of tunneling, zero-point vibrations, localization of the nuclei's wave function when narrow valleys of the PES are passed, steering of the approaching H_2 molecules towards low energy barrier configurations, and the time scales of the center of mass motion and the other degrees of freedom. Several ``established'' concepts, which were derived from low-dimensional dynamical studies, are shown to be not valid.

4 pages, 3 figures, submitted to Surf. Sci. Lett. Other related publications can be found at http://www.rz-berlin.mpg.de/th/paper.html

References in corpus (6)

• Six-Dimensional Quantum Dynamics of Adsorption and Desorption of H_2 at Pd(100): Steering and Steric Effects
• Ab initio Quantum and ab initio Molecular Dynamics of the Dissociative Adsorption of Hydrogen on Pd(100)
• Potential Energy Surface for H_2 Dissociation over Pd(100)
• Mechanism of Poisoning the Catalytic Activity of Pd(100) by a Sulfur Adlayer
• Influence of molecular vibrations on dissociative adsorption
• Ab initio calculation of the potential energy surface for the dissociation of H_2 on the sulfur covered Pd(100) surface