Reactive Scattering Dynamics at the Gas-Liquid Interface: Bridging the Gap between the Gas-Phase and Solution

气液界面的反应散射动力学：弥合气相和溶液之间的间隙

基本信息

批准号：
EP/M021823/1
负责人：
Matthew Costen
金额：
$ 103.02万
依托单位：
Heriot-Watt University
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2015
资助国家：
英国
起止时间：
2015 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FM021823%2F1
关键词：
Reactive Scattering Dynamics Gas Liquid

项目摘要

Anywhere the gas and liquid phases meet, chemistry occurs at the interface. Examples in the natural world include: respiration in living organisms; atmospheric aerosol particles; the surface of the sea on Earth; hydrocarbon particles in the atmosphere of Saturn's moon Titan. The chemistry of these interfaces is also vital in man-made environments as well: combustion of liquid fuels; industrial processes such as multiphase catalysis, gas sequestration and distillation. However, despite their importance, in comparison to the chemistry of reactions in the gas-phase or in solution, reactions at the gas-liquid interface are much less well understood. This project aims to deepen our fundamental understanding of reactions at liquid surfaces through a combination of cutting-edge experiment and theory. Consider a gas molecule approaching a liquid surface. The first encounter it makes with the surface will be an isolated event; the gas phase molecule will collide with a single molecule of the liquid surface. At this point the encounter is essentially the same as a gas phase collision between two isolated molecules. In the gas-phase, the molecules will then recoil and the encounter will be over. In some cases, collisions at the liquid surface will also result in the gas-phase molecule rebounding back into the gas-phase. However, it may instead go on to collide with further liquid surface molecules, and may even pass through the surface of the liquid and into solution, before eventually returning to the gas-phase. Reactions at the gas-liquid interface thus share characteristics of both the gas and solution phases, and by studying the dynamics of the reactions we can bridge the gap between them. This complements the intensive on-going effort in these hitherto largely separate areas, providing a unifying picture of molecular scattering dynamics. We will develop a new apparatus for our experiments, based on our previous experience in gas-liquid interfacial scattering, and combine it with high-resolution laser spectroscopy previously applied to study gas-phase dynamics. We will use this to study the reaction of CN radicals with liquid hydrocarbons, which forms HCN. The dynamics of this benchmark reaction process have been previously studied in the gas and solution phases. This reaction is not only of fundamental interest, as the CN radical is an important reactive species in extra-terrestrial atmospheres (e.g. atmosphere of Titan), and liquid hydrocarbon combustion. Simultaneously with the experiments, we will develop new theoretical models of the forces between the atoms present, and use those in calculations to simulate the dynamics of the reactions under experimental conditions. We will compare and combine the results of the experiments and theory to provide the most-detailed ever description of gas-liquid interfacial reaction dynamics. The fundamental insights into dynamics at the gas-liquid interface provided by this work will inform our understanding and modelling of the processes at gas-liquid interfaces in a wide range of environments vital to our society, e.g. atmospheric aerosols, liquid fuel combustion.

气体和液相相遇的任何地方，都会在界面发生化学。自然世界中的例子包括：生物体中的呼吸；大气气溶胶颗粒；地球上的海面；土星泰坦的大气中的碳氢化合物颗粒。这些界面的化学性质在人造环境中也至关重要：液体燃料的燃烧；工业过程，例如多相催化，气体隔离和蒸馏。然而，尽管它们的重要性与气相或溶液中的反应化学相比，气体液体界面的反应知之甚少。该项目旨在通过尖端实验和理论的结合加深我们对液体表面反应的基本理解。考虑接近液体表面的气体分子。它与表面进行的第一次相遇将是一个孤立的事件。气相分子将与液体表面的单个分子碰撞。在这一点上，遇到基本与两个分离分子之间的气相碰撞相同。在气相中，分子将后坐力，相遇将结束。在某些情况下，液体表面的碰撞还将导致气相分子反弹回气相。但是，它可以继续与进一步的液体表面分子相撞，甚至可以通过液体的表面并进入溶液，然后最终返回到气相。因此，气液界面的反应具有共享气体和溶液阶段的特征，并通过研究反应的动力学，我们可以弥合它们之间的间隙。这补充了这些迄今为止在很大程度上分开的区域中持续的持续努力，从而提供了分子散射动力学的统一图片。我们将根据我们先前在气体界面散射方面的经验开发一种新的实验设备，并将其与先前应用于研究气相动力学的高分辨率激光光谱法相结合。我们将使用它来研究CN自由基与形成HCN的液态烃的反应。先前已经在气体和溶液阶段研究了这种基准反应过程的动力学。该反应不仅具有根本的兴趣，因为CN自由基是事物外气（例如泰坦大气）和液态烃燃烧中的重要反应性物种。同时，我们将开发出存在原子之间力的新理论模型，并在计算中使用这些模型来模拟在实验条件下反应的动力学。我们将比较并结合实验和理论的结果，以提供对气体液体界面反应动力学有史以来最详细的描述。这项工作提供的气体液体界面上对动态的基本见解将为我们对我们社会至关重要的环境中的气体液体界面的过程的理解和建模，例如大气气溶胶，液体燃料燃烧。