H2020Индивидуална стипендия2017–2019

FCSpecTRe · Frequency Comb Spectroscopy of Temperature-dependent Reactions

„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“

Период: 2017-07-01 → 2019-06-30
Финансиране от ЕС: 183 455 €
Участници: 1
Схема: MSCA-IF-EF-ST

Линиите свързват координатора с партньорите.

Накратко на български

Химични реакции в газообразно състояние се проследяват чрез нов спектрометър, който едновременно измерва изчезването на реагентите и появата на продуктите. Данните помагат за създаването на по-точни модели на химичните процеси в земната атмосфера.

Този кратък обзор е генериран от изкуствен интелект

Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.

Резултати накратко

Frequency Comb Spectroscopy of Temperature-dependent Reactions

Gas phase chemical reactions are often monitored by the studying the loss of a reactant or growth of a product. For example, an infrared laser can be used in direct absorption techniques. If infrared light is incident on a gaseous sample where one of the molecules (reactant or product) absorbs light at that particular frequency by exciting a vibration, then the light intensity is attenuated. However, this technique is usually a highly specialized technique and specific to a single molecule since the laser used operates at a single narrow frequency. A new direct absorption spectrometer has been built in my lab using a broadband and high resolution mid-infrared light source, called a frequency comb laser. Any molecule that absorbs mid-infrared light can be monitored in this spectrometer, and with the high spectral resolution, molecules can be distinguished from one another. In this way, this spectrometer has molecular specificity but is also general to a wide range of molecules and so it can simultaneously monitor the loss of reactant and growth of a product during a chemical reaction. In addition, the spectrometer has rapid detection and high sensitivity, so it is able to monitor these molecules as a function of time to measure rates of reactions and is able to see very small, trace amounts of molecules formed. Many models of Earth’s atmosphere use information from complex chemical reactions to build up an understanding of the overall chemistry occurring. The multiplexed data on chemical reaction kinetics achieved with this spectrometer contributes a significant amount of information to these models, making them a more accurate representation of the chemistry occurring. The overall objectives of this project were to build a new spectrometer with dual detection techniques, fully characterize and optimize its performance, and apply this to the gas phase chemistry and spectroscopy of CH radical reactions. A significant part of the fellowship is also to undergo a series of training objectives to enable my transition into a fully independent, successful scientist, mentor of young scientists, and academic leader in my field.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз

Цел на проекта

This goal of this project is to obtain a deeper, molecular level understanding of chemical reactions important to atmospheric and planetary chemistry, specifically reactions involved in the oxidation of organic sulfur molecules. A common theme to experimentally determining chemical reaction rates is to monitor the disappearance of a reactant, perhaps even under pseudo-first order conditions. An ideal experiment, however, would monitor the loss of each reactant and the appearance of each product, under known temperature and pressure conditions, in order to gain a more complete picture of the reaction. This project is a significant step towards the ideal kinetic experiment. Here, mid-infrared cavity-enhanced direct frequency comb spectroscopy (CE-DFCS), a technology used almost exclusively in the physics community, will be used as a tool in the chemistry community to spectroscopically identify reactants, transient species, and products based on their vibrational absorption spectra. This is a rapid, sensitive, broadband, and high-resolution technique, which enables reaction rates to be derived based on the simultaneous measurement of both the reactant disappearance and product appearance. Moreover, CE-DFCS will be coupled to a pulsed Laval supersonic expansion, an essentially wall-less reactor with well-characterized pressure and temperature conditions. Temperature dependent rate constants will be measured over a wide temperature range, relevant to Earth’s atmosphere or even parts of the interstellar medium. This project has a strong interdisciplinary component, combining optical physics, fundamental physical chemistry, and atmospheric chemistry. This attribute arises from the significant two-way transfer of knowledge between the researcher and the Atmospheric and Planetary Chemistry group at the University of Leeds. In addition, the fellow will receive training during the tenure of the fellowship to enable her to become a successful independent scientist.

Оригинален текст от CORDIS (на английски).

Участници

UNIVERSITY OF LEEDS · LeedsКоординаторОбединеното кралство