Collaborative Research: A Nitrate Radical Oxidation Flow Reactor: Development and Use in Laboratory and Field Studies

该项目是一项合作努力，旨在开发一种新的工具来研究氮在大气中夜间化学中的作用。将建造一个现场可部署的氧化流动反应器(OFR)，以提供对硝酸根(NO3)引发的大气氧化老化过程的新见解。将在环境箱和OFRS中进行实验，以区分羟基(OH)和硝酸根在形成氧化挥发性有机化合物(OVOCs)和二次有机气溶胶(SOA)方面的相对贡献。这些物种可以对天气、气候和人类健康产生广泛的影响。这项工作解决了以下问题：(1)OFRs可以在多大程度上从VOC+NO3反应中重复产生OVOCs和SOA？(2)是从连续的多天氧化老化过程中形成的独特氧化产物，可以用来跟踪大气中的这些过程？(3)暴露在OFR中的NO3和OH自由基下的环境空气中OVOC和SOA的形成潜力是什么，作为综合氧化剂暴露和来源区域的函数，它是如何变化的？(4)环境空气中NO2-OFR的扰动是否能够更清楚地区分夜间N03和O3化学，特别是在识别不含氮的N03氧化产物方面？本项目支持几名研究生和一名早期职业研究人员。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This project is a collaborative effort to develop a new tool to study of the role of nitrogen in nighttime chemistry in the atmosphere. A field-deployable Oxidation Flow Reactor (OFR) will be built to provide new insights into nitrate radical (NO3)-initiated atmospheric oxidative aging processes. Experiments will be conducted in both environmental chambers and OFRs to distinguish the relative contributions of hydroxyl (OH) and nitrate radicals to the formation of oxidized volatile organic compounds (OVOCs) and secondary organic aerosol (SOA). These species can have widespread impacts on weather, climate, and human health.This effort addresses the following questions: (1) To what extent can OFRs reproducibly generate OVOCs and SOA from VOC + NO3 reactions? (2) Are unique oxidation products formed from sequential multi-day oxidative aging processes that can be used to trace these processes in the atmosphere? (3) What is the OVOC and SOA formation potential of ambient air exposed to NO3 versus OH radicals in an OFR, and how does it change as a function of integrated oxidant exposure and source region? (4) Can NO3-OFR perturbations of ambient air enable clearer delineation between nighttime NO3 and O3 chemistry, especially with respect to identifying non-nitrogen-containing NO3 oxidation products?This project supports several graduate students and an early career researcher.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.