Collaborative Research: Kinetics and Quantitative Spectroscopy for Redox Chemistry of Atmospheric Mercury

在化学系环境化学科学（ECS）项目的支持下，密西西比州立大学的Chuji Wang和锡拉丘兹纽约州立大学环境科学与林业学院的Theodore Dibble将结合尖端的光谱学和计算化学工具来测量溴化汞（HgBr）与各种大气自由基、臭氧和挥发性有机化合物的几个关键反应的速率常数。这里确定的机制和速率系数将对大气建模者在局部到全球尺度上改进汞化学分析有价值。拟议研究的社会效益在于减少汞对人类和环境健康的影响。这项研究的其他预期的更广泛的影响包括培训未来的研究人员在现代光谱学和计算化学；通过在课堂教学中开发学习模块和与当地高中生的互动，促进科学教育；透过各类本地科学活动，让公众参与科技活动；以及对从HBCU招收的本科生的培训。外展活动已计划，并涉及密西西比州和纽约州不同的当地社区。由密西西比州立大学的Chuji Wang和锡拉丘兹纽约州立大学环境科学与林业学院的Theodore Dibble组成的合作团队将利用多种光谱技术，包括在一个特殊设计的流动反应器中使用腔衰落光谱（CRDS）来确定速率系数作为温度和压力的函数。反应产物的绝对浓度和紫外光谱将通过CRDS测量。计算化学将用于指导实验和优化实验条件；实验将有助于验证和验证计算光谱。计算动力学和量子化学将用于研究以前未研究的副反应，并将实验结果扩展到大气条件的全部范围。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。

WIth support of the Environmental Chemical Sciences (ECS) Program in the Division of Chemistry, Chuji Wang at Mississippi State University and Theodore Dibble at the State University of New York College of Environmental Science and Forestry in Syracuse will combine cutting-edge tools of spectroscopy and computational chemistry to measure rate constants of several key reactions of mercury bromide (HgBr) with various atmospheric free radicals, ozone, and volatile organic compounds. The mechanisms and rate coefficients determined here will be valuable for atmospheric modelers to improve their analyses of mercury chemistry at local to global scales. The societal benefit of the proposed research lies in reducing the impact of mercury on human and environmental health. Additional anticipated broader impacts of this research include the training of future researchers in modern spectroscopy and computational chemistry; advancements in science education via the development of learning modules in classroom teaching and interactions with local high school students; public engagement with science and technology via various local science activities; and the training of undergraduate students recruited from an HBCU. Outreach activities are planned and involve diverse local communities in both Mississippi and New York.The collaborative team of Chuji Wang at Mississippi State University and Theodore Dibble at the State University of New York College of Environmental Science and Forestry in Syracuse will utilize multiple spectroscopic techniques including cavity ringdown spectroscopy (CRDS) in a specially-designed flow reactor to determine rate coefficients as a function of temperature and pressure. Absolute concentrations and UV spectra of reaction products will be measured via CRDS. Computational chemistry will be used to guide experiments and optimize experimental conditions; and experiments will help validate and verify computed spectra. Computational kinetics and quantum chemistry will be used to investigate previously unstudied side reactions and to extend experimental results to the full range of atmospheric conditions.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.