Collaborative Research: Laboratory Studies of the Role of Organic Peroxy Radicals (RO2) Chemistry on the Evolution of Atmospheric Organic Carbon

该项目的目标是提高对反应化学和有机化合物大气氧化的认识。一套仪器将在实验室中使用，以更全面地了解某些化学制度如何在大气氧化过程中控制气相和气溶胶产物的数量、特性和性质。该项目将为大气有机气溶胶形成的化学基础提供新的见解，有机气溶胶是影响空气质量和全球气候的重要组成部分。该项目重点研究过氧自由基（RO2）化学及其如何控制有机化合物在大气氧化过程中形成的反应产物的分布。挥发性有机化合物将在精心控制的RO2反应条件下在环境室中氧化，并使用一套实时飞行时间质谱技术测量所得产物的形成和演化，以提供有关浓度、化学式、氧化状态和有机物种挥发性的信息。主要产出包括气相和颗粒相产物的综合测量、挥发性分布（包括二次有机气溶胶产量）和不断变化的OH反应性。最后，将对反应混合物的关键系综性质（如碳氧化态、碳数）的测量结果与最先进的大气化学机制的预测结果进行比较。该项目的结果可用于3D模型，随时间变化的浓度将作为社区资源公开提供，用于测试和完善大气氧化和二次有机气溶胶形成的最先进模型。该项目包括对早期职业科学家的培训，包括研究生和本科生。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The goal of this project is to improve knowledge about reactive chemistry and the atmospheric oxidation of organic compounds. A suite of instruments will be used in the laboratory to develop a more complete understanding of how certain chemical regimes control the amount, identity, and properties of gas-phase and aerosol products during atmospheric oxidation. This project will yield new insights into the chemistry underlying the formation of atmospheric organic aerosol, an important component influencing air quality and global climate.This project is focused on peroxy radical (RO2) chemistry and how it controls the distribution of reaction products formed during the atmospheric oxidation of organic compounds. Volatile organic compounds will be oxidized in an environmental chamber under carefully-controlled RO2 reaction conditions, and the formation and evolution of the resulting products will be measured using a suite of real-time time-of-flight mass spectrometric techniques to provide information on the concentration, chemical formula, oxidation state, and volatility of organic species. Key outputs include comprehensive measurements of gas- and particle-phase products, volatility distributions (including secondary organic aerosol yields), and evolving OH reactivities. Finally, measurements of key ensemble properties of the reaction mixture (e.g., carbon oxidation state, carbon number) will be compared against predictions from state-of-the-art atmospheric chemical mechanisms. Results from this project can be used in 3D models, and time-dependent concentrations will be made publicly available as a community resource for testing and refining state-of-the-art models of atmospheric oxidation and the formation of secondary organic aerosol. This project includes training for early-career scientists, including both graduate and undergraduate students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.