Quantum-State-Resolved Studies of Gas-Surface Interaction Dynamics

在这个由化学部实验物理化学计划支持的项目中，SITZ将执行涉及分子氢和反应性过渡金属表面的状态对状态实验。实验的重点将是氢/铜和氢/钯体系。将研究平移、旋转和振动运动以及分子排列在决定散射事件结果中的相对重要性。入射到表面的氢分子将通过受激拉曼散射在选定的转动和振动状态下制备。在一些实验中，入射分子的角动量矢量会相对于表面法线对齐，以研究相互作用中的空间效应。也将通过测量非弹性跃迁几率来研究与表面碰撞后未幸存的受激发分子的命运。了解气体-表面相互作用的核心是了解可用自由度在动力学中发挥的重要性。这个项目中的实验将通过观察入射分子在定义的量子力学状态下与表面相互作用的结果来深入了解简单表面反应的动力学。收集的高质量数据将用于比较和检验气体-表面相互作用的高级理论描述。

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.