Dynamical quantum processes of molecular beams at surfaces: Dissociative adsorption of hydrogen on metal surfaces

SURFACE SCIENCE

卷:363

Article; Proceedings Paper

关键词: atom-solid interactions, scattering, diffraction;    chemisorption;    computer simulations;    copper;    density functional calculations;    hydrogen;    low index single crystal surfaces;    metallic surfaces;    models of surface chemical reactions;    molecule-solid reactions;    palladium;    quantum effects;    sticking;    surface chemical reaction;    thermal desorption;   

DOI  :  10.1016/0039-6028(96)00070-2

来源: Elsevier

【 摘 要 】

Due to the improvement of computer power and the development of efficient algorithms it is now possible to combine high-dimensional quantum dynamical calculations of the dissociative adsorption of molecular beams with reliable ab-initio potential energy surfaces (PES). In this brief review two recent examples of such studies of the systems H-2/Cu(lll), where adsorption is hindered by a noticeable energy barrier, and H-2/Pd(100), where activated as well as non-activated paths to adsorption exist, are presented. The effect of lateral surface corrugation on the sticking probability in the tunneling and the classical regime and the role of additional parallel momentum are discussed in the context of the H-2/Cu(lll) results. For the system H-2/Pd(100) it is shown that the initial decrease of the sticking probability with increasing kinetic energy, which is usually attributed to a precursor mechanism, can be explained by dynamical steering. In addition, the influence of rotation on the adsorption and desorption dynamics is examined.

【 授权许可】

Free