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

合作研究：相关温度和湿度下矿物气溶胶与大气气体混合物异质相互作用的实验室和理论研究

• 批准号: 0928121
• 负责人: Courtney Hatch
• 金额: $ 16.87万
• 依托单位: Hendrix College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0928121&HistoricalAwards=false
• 关键词: Collaborative; Research; Laboratory; Theoretical; Studies

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.

该项目的目标是确定天然矿物气溶胶成分（代表化学处理和新排放的矿物气溶胶）在大气相关温度和湿度范围内与单一大气气体和气态混合物的异质反应性。配备反应室的低压、低温漫反射红外傅里叶变换光谱仪（DRIFTS）将用于进行实验室研究。该室系统允许对代表在大气中观察到的矿物成分薄膜上反应气体和气态混合物的异质吸收进行原位同步气相和凝相测量。将通过实验研究异质吸收随温度、相对湿度和反应气体浓度的变化。相关的理论研究将（a）通过解释红外光谱和识别中间和末端吸附反应产物来补充实验，提供额外的机制细节，（b）模拟所研究的矿尘成分的电子特性并确定金属杂质对表面反应性的影响，以及（c）确定矿尘表面的异质反应如何改变这些电子特性。研究结果将提供重要的机制， 纳入当前大气化学模型所需的动力学和热力学细节，以便更准确地模拟地球大气中异质反应性（对对流层化学的影响）、表面成分（对健康、气候和进一步反应性的影响）和水吸附（对能见度和气候的影响）的影响。这项工作将超越之前对矿物粉尘气溶胶异质化学的研究，这些研究仅限于干燥条件、室温和仅存在单一反应气体的情况下的异质吸收。该项目将促进一所大型大学和一所小型文理学院之间的独特合作伙伴关系。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。除了传统的传播之外，研究成果还将纳入亨德里克斯学院的本科教学课程。此外，亨德里克斯学院将使用 DRIFTS 系统举办实践研讨会和实验室实验。