Collaborative Research: Laboratory and Theoretical Studies of Mineral Aerosol Heterogeneous Interactions with Mixtures of Atmospheric Gases at Relevant Temperatures and Humidities

该项目的目标是确定以化学处理和新排放的矿物气溶胶为代表的天然矿物气溶胶成分与单一大气气体以及与大气有关的温度和湿度范围内的气体混合物的异质反应性。将使用配备有反应室的低压、低温漫反射红外傅里叶变换光谱仪(DRIFT)进行实验室研究。该小室系统允许对反应气体和气体混合物在代表大气中观察到的矿物成分的薄膜上的异相吸收进行原位、同时的气相和凝聚相测量。多相吸收将作为温度、相对湿度和反应气体浓度的函数进行实验研究。相关的理论研究将(A)通过解释红外光谱和识别中间和终端吸附的反应产物来补充实验，提供额外的机理细节，(B)模拟所研究的矿物粉尘组分的电子性质并确定金属杂质对表面反应性的影响，以及(C)确定矿物粉尘表面上的非均相反应如何改变这些电子性质。这些研究结果将提供纳入当前大气化学模型所需的重要的机理、动力学和热力学细节，以便更准确地模拟非均相反应性(对对流层化学的影响)、表面组成(对健康的影响，气候和进一步的反应性)和地球大气中的水吸附(对能见度和气候的影响)。这项工作将超越以前对矿物粉尘气溶胶非均相化学的研究，这些研究仅限于在干燥条件、室温和只存在单一反应气体的情况下进行非均相吸收。该项目将在一所大型大学和一所小型文理学院之间建立独特的合作伙伴关系。这种关系将通过为本科生提供积极的教育研究机会来培养体验式学习，并帮助招收训练有素、以科学为导向的本科生和研究生。除了传统的传播，研究成果将被纳入亨德里克斯学院的本科教学课程。此外，将在亨德里克斯学院使用漂移系统进行动手讲习班和实验室实验。

The objective of this project is to determine the heterogeneous reactivity of natural mineral aerosol components, representative of chemically-processed and freshly-emitted mineral aerosol, with single atmospheric gases and with gaseous mixtures over atmospherically relevant temperature and humidity ranges. A low-pressure, low-temperature Diffuse Reflectance Infrared Fourier Transform Spectrometer (DRIFTS) equipped reaction chamber will be used to carry out laboratory studies. The chamber system allows for in situ, simultaneous gas- and condensed-phase measurements of the heterogeneous uptake of reactive gases and gaseous mixtures on thin films of mineral components representative of those observed in the atmosphere. Heterogeneous uptake will be studied experimentally as a function of temperature, relative humidity and reactive gas concentration. Associated theoretical studies will (a) complement experiments by interpreting infrared spectra and identifying intermediate and terminal adsorbed reaction products, providing additional mechanistic detail, (b) model electronic properties of the mineral dust components studied and determine the effects of metal impurities on surface reactivity, and (c) determine how heterogeneous reactions on mineral dust surfaces alter these electronic properties.Results of the studies will provide important mechanistic, kinetic and thermodynamic details needed for incorporation into current atmospheric chemistry models in order to more accurately model the effects of heterogeneous reactivity (impacts on tropospheric chemistry), surface composition (impacts on health, climate and further reactivity) and water adsorption (impacts on visibility and climate) in the Earth's atmosphere. The work will extend beyond previous studies of mineral dust aerosol heterogeneous chemistry that were limited to heterogeneous uptake under dry conditions, room temperature and in the presence of only a single reactive gas. The project will foster a unique partnership between a large university and a small liberal arts college. This relationship will cultivate experiential learning via active educational research opportunities for undergraduate students and aid in the recruitment of well-trained, science-oriented students at the undergraduate and graduate levels. Beyond traditional dissemination, research results will be incorporated into undergraduate teaching curricula at Hendrix College. Additionally, hands-on workshops and laboratory experiments will be conducted at Hendrix College using the DRIFTS system.