Faraday joint interest group conference 2023

Atmospheric degradation chemistry of sustainable solvents Terry J. Dillon 1 , Caterina Mapelli 1 , Abbie Robinson 1 , C. Rob McElroy 1 , Conor D. Rankine 1 , Andrew R. Rickard 1 , Claudiu Roman 2 , Iustinian Bejan 2 , Daniel Hollas 3 , Basile F. E. Curchod 3 1 Department of Chemistry, University of York, UK, 2 Alexandru Ioan Cuza University, Romania, 3 School of chemistry, University of Bristol, UK Solvents are a large and persistent contributor to man-made air pollution. Scientists have designed safe and sustainable new “green” solvents to replace toxic, unsustainable, petroleum-derived solvents. However, whilst traditional solvents such as toluene are notorious atmospheric pollutants, there is little to no photochemical data on the fate of these new compounds, from which to predict air quality impacts. In this work, lab-based and computational experiments were deployed to study the atmospheric degradation of several promising “green” solvents. An important degradation route for all solvents studied was via reaction with the hydroxyl radical. A combination of absolute laser-based experiments, relative rate experiments and quantum chemical calculations revealed complex non-Arrhenius kinetic behaviour for these reactions in standard atmospheric conditions. For some solvents containing carbonyl functionality, direct UV photolysis was also an important degradation route. A combination of UV-vis. spectroscopic experiments and quantum chemical calculations demonstrated that photolysis is poorly characterised and likely underestimated in current state-of-science models. Air quality impacts of these new solvents was assessed via calculation of atmospheric lifetimes and photochemical ozone production potentials, and comparison with the traditional solvents they may replace.

P18

© The Author(s), 2023

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