Heterogeneous Chemistry and Photochemistry in the Troposphere: Reactions of Mineral Dust and Other Metal-Containing Particle Surfaces at the Gas-Solid and Liquid-Solid Interface

美国国家科学基金会化学部的环境化学科学项目支持爱荷华大学的Vicki H. Grassian教授的研究，该研究将重点研究矿物粉尘和含金属颗粒在气固和液固界面处的微量大气气体的化学和光化学。发生在这些表面上的化学反应可以改变关键大气成分的气相浓度，并显著改变颗粒的物理化学性质。在环境中，这些界面以气溶胶和静止表面的形式存在。在拟议的研究中，研究了大气气体与矿物粉尘和含金属颗粒组分的反应，以便更好地了解对流层的化学性质以及这些反应对环境的影响。将研究几个不同的方面，包括有机酸与矿物粉尘颗粒的非均相化学，大气气体对矿物粉尘气溶胶的光活性成分的非均相化学和人为含金属氧化物颗粒的表面反应，这些颗粒是大气气溶胶和固定表面的成分。这些反应发生在不同的水活度下，因此，不同的水相包括气固界面上的吸附水和液固界面上的液态水。拟议的活动侧重于更好地理解发生在气溶胶和静止粒子表面的基本化学反应。如果没有这些类型的基础研究，就没有什么信息可以纳入大气和环境模型模拟，也就没有什么对这种可能影响环境的潜在重要化学反应的理解。除了与更好地了解自然和受人类影响的环境有关的更广泛的影响外，这项研究的另一个重要组成部分是拟议的教育和推广活动。其中包括对本科生和研究生的培训。PI有一个研究项目，吸引了各种各样的学生，包括许多女性和代表性不足的少数民族。拓展活动包括为K-12学生及其家长等更广泛的公众开展动手活动。PI正在努力扩大和提高爱荷华大学文理学院各院系和中心的STEM（科学、技术、工程和数学）推广和教育的有效性。

The Environmental Chemical Sciences Program in the Chemistry Division at the National Science Foundation supports the research of Professor Vicki H. Grassian at the University Iowa that will focus on the chemistry and photochemistry of mineral dust and metal-containing particles with trace atmospheric gases at the gas-solid and liquid-solid interface. The chemistry that occurs on these surfaces can alter gas phase concentrations of key atmospheric constituents as well as significantly change the physicochemical properties of the particles. In the environment, these interfaces are present as both aerosol and stationary surfaces. In the proposed studies, reactions of atmospheric gases with components of mineral dust and metal-containing particles are investigated to better understand the chemistry of the troposphere and the impact that these reactions have on the environment. Several different aspects will be investigated and include the heterogeneous chemistry of organic acids with mineral dust particles, the heterogeneous chemistry of atmospheric gases on photoactive components of mineral dust aerosol and surface reactions of anthropogenic metal-containing oxide particles, which are components of atmospheric aerosol as well as stationary surfaces. These reactions take place under different regimes of water activity and, therefore, different phases of water including adsorbed water at the gas-solid interface and liquid water at the liquid-solid interface.The proposed activities focus on better understanding the fundamental chemistry that occurs at aerosol and stationary particle surfaces. Without these types of fundamental studies, there would be little information to incorporate into atmospheric and environmental model simulations and there would be little understanding of this potentially important reaction chemistry that may impact the environment. Besides broader impacts related to better understanding the natural and human-impacted environment, another important component of this research is in the educational and outreach activities that are proposed. These include training of undergraduate and graduate students. The PI has a research program that attracts a diverse group of students including many women and underrepresented minorities. Outreach activities include the development of hands-on activities for the broader public that spans K-12 students and their parents. The PI is leading efforts to expand and enhance the effectiveness of STEM (Science, Technology, Engineering and Mathematics) outreach and education in departments and centers within the College of Liberal Arts and Sciences at the University of Iowa.