Quantum State Resolved Studies of Gas-Surface Interaction Dynamics

气体-表面相互作用动力学的量子态解析研究

• 批准号: 9512232
• 负责人: Greg Sitz
• 金额: $ 29.42万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-12-01 至 1999-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9512232&HistoricalAwards=false
• 关键词: Quantum; State; Resolved; Studies; Gas

In this project in the PhysicalChemistry program of the Chemistry Division, Professor Greg O. Sitz of the Chemistry Department of the University of Texas at Austin will perform a series of gas-surface scattering experiments. A combination of molecular beam and laser based state preparation and detection techniques will be used to performm fully quantum state resolved studies of gas-surface interaction dynamics. The scattering and dissociation of molecular hydrogen and deuterium from single crystal copper surfaces will be studied to determine the relative importance of translational, rotational, vibrational and molecular alignment in dermining the outcome of the scattering event. Stimulated Raman scattering will be used to prepare hydrogen molecules incident on the copper surface in a selected rotational state of the first excited vibrational state. Scattered molecules will be detected in a quantum state specific manner by multiphoton ionization. The initial encounter of a molecule with a solid surface can lead to several possible results depending on the molecule , the surface, and the energy partitioning amongst the many available degrees of freedom. These possibilities include inelastic scattering, trapping, sticking and bond breaking. In the last case, a bond in the molecule can be broken, paying the energy price by forming one or more chemical bonds to the surface. This is the essence of the ability of many surfaces to promote or participate in chemical reactions. In many cases of interest, however, even though the reaction is energetically favorable, the reaction probability is low because of the presence of a barrier: the reaction is said to be activated. Of central concern is the nature of this activation barrier and the dynamical mechanism for crossing it. This research focuses on gas-surface interactions in systems where dissociative adsorption is an activated process. By performing this research with fully state resolved measurements new insight into surface dynamics will be gained and existing theories will be stringently tested.

在这个项目中的物理化学计划的化学 格雷格·O教授北京大学化学系 德克萨斯大学奥斯汀分校将进行一系列的气体表面 散射实验 基于分子束和激光的组合 国家准备和检测技术将用于充分执行 气体-表面相互作用动力学的量子态分辨研究。 的 分子氢和氘的散射和离解 单晶铜表面将进行研究，以确定相对 平移、转动、振动和分子重要性 在确定散射事件的结果中的对准。 刺激 拉曼散射将用于制备氢分子入射到 铜表面处于第一激发的所选旋转状态， 振动态 散射的分子将在量子中被检测到 状态特定的方式通过多光子电离。 一个分子与固体表面的初次相遇会导致 几种可能的结果取决于分子，表面和 在许多可用的自由度之间进行能量分配。 这些 可能性包括非弹性散射、捕获、粘附和粘结 绝命毒 在最后一种情况下，分子中的一个键可以被打破， 通过与表面形成一个或多个化学键来降低能量价格。 这是许多表面促进或 参与化学反应。然而，在许多令人感兴趣的情况下， 即使反应在能量上是有利的， 由于存在屏障，反应的可能性很低： 据说被激活了。 最令人关注的是这种情况的性质 激活障碍和动力学机制跨越它。这 研究重点是系统中的气体-表面相互作用， 解离吸附是活化过程。 通过执行该 全状态分辨测量研究对表面的新认识 将获得动力，并严格检验现有理论。