In this project supported by the Experimental Physical Chemistry Program of the Chemistry Division, Sitz will perform state-to-state experiments involving molecular hydrogen and reactive transition-metal surfaces. The focus of the experiments will be the hydrogen/copper and hydrogen/palladium systems. The relative importance of translational, rotational, and vibrational motion and molecular alignment in determining the outcome of scattering events will be investigated. Hydrogen molecules incident on the surface will be prepared in selected rotational and vibrational states using stimulated Raman scattering. In some experiments the angular momentum vector of incident molecules will be aligned with respect to the surface normal to study steric effects in the interaction. The fate of the excited molecules which do not survive the collision with the surface will also be investigated by measuring inelastic transition probabilities.
Central to understanding gas-surface interactions is knowledge of the importance that available degrees of freedom play in the dynamics. The experiments in this project will provide insight into the dynamics of simple surface reactions by looking at the results of interactions of incident molecules in defined quantum mechanical states with surfaces. The high quality data collected will be used to compare with and test high level theoretical descriptions of gas-surface interactions.
