We report zero-coverage reaction probabilities (S0) for HCl dissociative adsorption on Au(111) obtained by the seeded molecular beam hot-nozzle method. For measurements at normal incidence with mean translational energies ranging from 0.94 to 2.56 eV (nozzle temperatures 296 to 1060 K), S0 increased from 6 × 10-6 to 2 × 10-2. S0Â also increased with increasing nozzle temperature for fixed incidence energy associated with the motion normal to the surface. Accounting for the influence of the vibrational state population and translational energy distributions in the incident beam, we are able to compare the experimental results to recent theoretical predictions. These calculations, performed employing 6-D quantum dynamics on an electronically adiabatic potential energy surface obtained using density functional theory at the level of the generalized gradient approximation and the static surface approximation, severely overestimate the reaction probabilities when compared with our experimental results. We discuss some possible reasons for this large disagreement.
Bibliographical noteFunding Information:
We acknowledge support from the Deutsche Forschungsgemeinschaft CRC1073 under project A04 and from the Ministerium f?r Wissenschaft und Kultur Niedersachsen and the Volkswagenstiftung under grant no. INST 186/901-1. A.M.W. and D.J.A. acknowledge support from the Alexander von Humboldt Foundation. J.G. acknowledges support from the Max Planck - EPFL Center for Molecular Nanoscience and Technology. I.R. and A.M.W. acknowledge support from the Nieders?chsisch-Israelische Gemeinschaftsvorhaben under project no. 574 7 022. We also thank Dmitriy Borodin for his assistance in the experiments and Prof. Dirk Schwarzer for providing the pulsed nozzle.