Atmospheric Impacts of Criegee Biradical Chemistry

Criegee 双自由基化学的大气影响

• 批准号: NE/L010798/1
• 负责人: Daniel Stone
• 金额: $ 65.71万
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2014
• 资助国家: 英国
• 起止时间: 2014 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FL010798%2F1
• 关键词: Atmospheric; Impacts; Criegee; Biradical; Chemistry

Poor air quality costs the UK in excess of £20billion per year. This poor air quality is controlled by the chemical composition of the atmosphere, and the interactions between the multitude of different chemical species in the atmosphere. These interactions are typically mediated by highly reactive trace gas species, leading to chemical transformations which control not only air quality but also ozone depletion and climate change. Our understanding of the vast array of chemical compounds and their transformations in the atmosphere dictates our ability to understand, predict, and address these environmental problems.For many years, one class of trace species known as Criegee biradicals have been theorised to participate in chemical transformations in the atmosphere, both in regions dominated by natural processes and in those influenced by man. Owing to their high reactivity and transient nature, Criegee biradicals have proven difficult to measure directly, leading to large uncertainties in their chemistry and their impacts on atmospheric composition. Recent ground-breaking experiments led to the first direct observations of Criegee biradicals, and showed them to be much more reactive than previously anticipated on the basis of indirect measurements and theoretical calculations. The simplest Criegee biradical (CH2OO) was shown to react with sulfur dioxide (SO2) 1000 times faster than previously expected, potentially revealing a previously unknown route for production of sulfur trioxide (SO3) in the atmosphere and impacting our understanding of atmospheric production of sulfuric acid, acid rain and sulfate aerosol, with implications for both air quality and climate change. However, these experiments were performed at low pressures (less than 1 % of atmospheric pressure), and the reaction rate and products at higher pressures relevant to the atmosphere may be different to those observed in the low pressure experiments. Assessment of the atmospheric impacts of a reaction requires knowledge of both the rate of the reaction and the product yields.This work will take advantage of the new opportunities to explore the chemistry and impacts of Criegee biradicals in the atmosphere, using techniques which will enable investigation of both reaction rates and product yields at temperatures and pressures relevant to the atmosphere. Initial experiments will be performed with existing experimental apparatus in the School of Chemistry at the University of Leeds. Subsequent experiments, in collaboration with project partners at the Sandia National Laboratory in California, will develop novel instrumentation to monitor Criegee biradicals and their reaction products at atmospheric temperatures and pressures under idealised conditions in the laboratory. The instrumentation developed during the fellowship will be applied to measurements of Criegee biradicals in more complex systems in an atmospheric reaction chamber in Leeds, and has the potential for future development to field measurements of Criegee biradicals in the atmosphere.Atmospheric impacts of experimental results obtained in this work will be assessed through the use of detailed numerical models of the atmosphere, in collaboration with world-leading research groups at the University of York and the Massachusetts Institute of Technology (MIT).

英国每年的空气质量差为200亿英镑。这种差的空气质量受大气的化学成分以及大气中众多不同化学物种之间的相互作用控制。这些相互作用通常是由高反应性微量气体物种介导的，导致化学转化不仅控制空气质量，还可以控制臭氧的耗竭和气候变化。我们对大量化合物及其在大气中的转化的理解决定了我们理解，预测和解决这些环境问题的能力。多年来，理论上已经将一种称为Criegee Biradicals的痕量物种参与了大气中的化学转化，这两种物种在自然过程中占主导地位，以及在自然过程中占主导地位。由于其高反应性和瞬时性质，Criegee Biradicals被证明很难直接测量，从而导致其化学反应不确定性及其对大气组成的影响。最近的开创性实验导致了Criegee Biradicals的首次直接观察，并表明它们比以前在间接测量和理论计算的基础上预期的更具反应性。显示出最简单的Criegee Biradical（CH2OO）与二氧化硫（SO2）的反应速度（SO2）比以前预期的快1000倍，可能揭示了先前未知的三氧化硫生产途径（SO3），并影响了我们对硫酸，酸性雨水和硫酸盐的大气产生的理解，并与硫酸盐和硫酸盐的大气产生有关，并伴随着硫酸盐和硫酸盐的含义，这两种空中都可以变化。但是，这些实验是在低压（不到大气压的1％）下进行的，并且与大气相关的较高压力的反应速率和产物可能与低压实验中观察到的反应速率和产物不同。评估反应的大气影响需要了解反应速率和产物产量。这项工作将利用新的机会来探索Criegee Biradicals在大气中的化学和影响，并使用与大气相关的反应速度和产品产量的投资，以促进反应速度和产品的投资。最初的实验将使用利兹大学化学学院的现有实验仪进行。随后的实验，与加利福尼亚州桑迪亚国家实验室的项目合作伙伴合作，将在实验室中理想化的条件下，在大气温度和压力下，在大气温度和压力下开发新颖的仪器，以监测Criegee Biradicals及其反应产品。 The instrumentation developed during the fellowship will be applied to measurements of Criegee biradicals in more complex systems in an atmospheric reaction chamber in Leeds, and has the potential for Future development to field measurements of Criegee biradicals in the atmosphere.Atmospheric impacts of experimental results obtained in this work will be assessed through the use of detailed numerical models of the atmosphere, in collaboration with world-leading research groups at the University of York and the马萨诸塞州理工学院（MIT）。

项目成果

Impacts of bromine and iodine chemistry on tropospheric OH and HO<sub>2</sub>: Comparing observations with box and global model perspectives

溴和碘化学对对流层 OH 和 H2O 的影响

• DOI: 10.5194/acp-2017-892
• 发表时间: 2017
• 作者: Stone D

Measurement of OH reactivity by laser flash photolysis coupled with laser-induced fluorescence spectroscopy

激光闪光光解与激光诱导荧光光谱法测量 OH 反应性

• DOI: 10.5194/amt-2016-51
• 发表时间: 2016
• 作者: Stone D

Kinetics of the gas phase reaction of the Criegee intermediate CH2OO with SO2 as a function of temperature.

Criegee 中间体 CH2OO 与 SO2 的气相反应动力学随温度的变化。

• DOI: 10.1039/d1cp02932k
• 发表时间: 2021
• 期刊: PCCP
• 作者: Onel L