CAS-Climate: Interfacial Reactions of Model Wildfire and Combustion Emissions

This project is jointly funded by the Environmental Chemical Sciences (ECS) Program of the Chemistry Division and the Established Program to Stimulate Competitive Research (EPSCoR) Program. Biomass burning emissions, including those from the combustion of wood for residential heating, release large quantities of catechol pollutant into the air. In the atmosphere, catechol contributes to form particulate matter and interacts with available mineral surfaces in ways that have eluded prior attention and can reduce visibility, worsen air quality, and affect climate. With this project, Professor Marcelo Guzman and his team at the University of Kentucky investigate a possible mechanism to produce sunlight absorbing chemicals from catechol in air. The project generates knowledge about the chemistry of wildfire and combustion emission on the surface of minerals with direct implications to air quality, public health, and climate. The project provides interdisciplinary training in environmental chemistry and environmental science to Kentucky’s graduate and undergraduate students. The project introduces novel pollution and separation knowledge to students from a public elementary school from underserved communities through educational activities built upon the proposed research. The study of interfacial photoreactions is at the forefront of atmospheric chemistry research to understand the fate of catechol, an abundant biomass burning pollutant, and explains the role played by mineral surfaces in the atmosphere. This project aims to reveal new mechanistic understanding of the transformation of catechol on mineral surfaces that are excited under sunlight irradiation. Specifically, the project will investigate the novel production of reactive oxygen species (e.g., OH radical and singlet molecular oxygen) by chromophores that can enhance the processing of pollutants on the surface of atmospheric particles. The project will create advanced experimental methods and utilize a combination of several spectroscopy, chromatography, and mass spectrometry techniques to study surface reactions under environmentally relevant sunlight and humidity conditions. The project will reveal electronic transitions of species produced on environmental interfaces, their structures, reaction kinetics, and other physical properties that impact air quality, public health, and climate. 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.