Transport and Reactivity at the Ionic Liquid-Gas Interface

在这项由化学结构、动力学和机理-化学系计划支持的项目中，蒙大拿州立大学的Timothy K.Minton教授和他的团队探索了离子液体(ILS)表面的化学结构和反应性，这是一类正在发现重要应用的液体，例如，在气体分离和催化中。ILS对于可持续的化学加工也具有潜在的重要性，因为它们是非挥发性的，不会被热降解。Minton小组将原子束和分子束定向到ILS表面，并从表面出现的原子和分子的角度、速度和身份推断表面结构和化学反应的细节。实验结果与理论计算(也是由Minton小组进行的)进行了比较。该项目的最终目标是实现一种“理解驱动”的方法来设计和优化有用的离子液体系统。该项目使用基于质谱学检测的实验原子和分子束散射技术，这是一种提供精细动态散射数据的通用技术，不依赖于仅限于相对较少的散射物种的光谱检测方案。这些实验与液体表面的分子动力学模拟和气体-表面相互作用动力学的混合量子力学/分子力学计算密切相关。这一联合实验/计算项目扩大了原子和分子在离子液体表面上的非弹性和反应性碰撞的范围，目的是(1)扩大反应原子作为液体表面结构的分析探针的用途，(2)量化影响试剂气体和负载型离子液体(SILP)催化剂之间联系的因素，以及(3)揭示离子液体表面控制两个试剂分子反应的机理。通过创建一个新的互动散射动力学网络应用程序，积极促进推广，该应用程序采用图形用户界面，通过预先装入的课程和用户指导的实验，使原子-表面散射过程可视化。ISD网络应用程序可以预装在平板电脑或笔记本电脑浏览器选项卡上，因此提供了非常便携的教学/学习资源，以帮助理解液体表面结构和气液碰撞动力学。

In this project supported by the Chemical Structure, Dynamics, and Mechanisms-A Program of the Division of Chemistry, Prof. Timothy K. Minton and his group at Montana State University explore the chemical structure and reactivity of the surfaces of ionic liquids (ILs), which are a class of liquids that are finding important applications, for example, in gas separation and catalysis. ILs are also potentially important for sustainable chemical processing because they are non-volatile and resistant to degradation by heat. The Minton group directs beams of atoms and molecules at the surfaces of ILs, and infers details about surface structure and chemical reactivity from the angles, velocities, and identities of the atoms and molecules that emerge from the surface. The experimental results are compared with theoretical calculations (also done by the Minton group). The ultimate goal of this project is to enable an "understanding-driven" approach to designing and optimizing ionic liquid systems for useful applications.The project uses experimental atomic and molecular beam scattering techniques based on mass-spectrometric detection, which is a general technique that provides dynamical scattering data in exquisite detail and does not rely on spectroscopic detection schemes that are limited to relatively few scattered species. The experiments are being closely linked with molecular dynamics simulations of liquid surfaces and mixed quantum mechanics/molecular mechanics calculations of gas-surface interaction dynamics. This joint experiment/computation project expands the scope of inelastic and reactive collisions of atoms and molecules on IL surfaces, with aims to (1) extend the use of reactive atoms as analytical probes of liquid surface structure, (2) quantify the factors that influence the connection between reagent gases and supported IL-phase (SILP) catalysts, and (3) uncover the mechanisms by which an ionic liquid surface may control the reaction of two reagent molecules. Outreach is actively promoted through the creation of a new Interactive Scattering Dynamics (ISD) web app, which is employing a graphical user interface to visualize atom-surface scattering processes through preloaded lessons and through user directed experimentation. The ISD web app may be preloaded on a tablet or laptop browser tab, thus providing a very portable teaching/learning resource to aid understanding of liquid surface structure and the dynamics of gas-liquid collisions.