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

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.