Sticking of molecular hydrogen on simple, noble and transition metal surfaces

Abstract

Abstract The dynamics of adsorption for molecular hydrogen on different metal surfaces (Ni, Cu, A1) is discussed in this review. Surface parameters like geometric and electronic structure, surface defects and impurities, surface coverage and surface temperature as well as gas parameters like translational, vibrational and rotational energy and angle of incidence influence the sticking probability of H2. On transition metal surfaces the sticking coefficient is rather high, whereas on noble and simple metals the sticking coefficient is exceedingly small. Only translationally and/or vibrationally hot molecules are able to adsorb on the latter surfaces. These features are discussed in the context of appropriate potential energy surfaces which govern the adsorption process. Experimental methods to determine absolute sticking coefficients as function of different gas parameters are also described.