Publication: Gas-phase oxidation rates and products of 1,2-dihydroxy isoprene
Publication - Gas-phase oxidation rates and products of 1,2-dihydroxy isoprene
Gas-phase oxidation rates and products of 1,2-dihydroxy isoprene
Publication Year: 2021
Author list: Kelvin H. Bates, James D. Cope, Tran B. Nguyen
Journal Short Name: Environ. Sci. Technol.
Publisher: American Chemical Society
Abstract1,2-Dihydroxy isoprene (1,2-DHI), a product of isoprene oxidation from multiple chemical pathways, is produced in the atmosphere in large quantities; however, its chemical fate has not been comprehensively studied. Here, we perform chamber experiments to investigate its gas-phase reactions. We find that the reactions of 1,2-DHI with OH radicals and ozone are rapid (kOH = 8.0 (±1.3) × 10–11 cm3 molecule–1 s–1; kO3 = 7.2 (±1.1) × 10–18 cm3 molecule–1 s–1). Reaction with OH, which dominates 1,2-DHI loss, leads primarily to fragmentation and radical recycling; major products under both high- and low-NO conditions include hydroxyacetone, glycolaldehyde, and 2,3-dihydroxy-2-methyl-propanal (DHMP). Radical-terminating hydroperoxide formation from the peroxy radical (RO2) reaction with HO2 and organonitrate formation from RO2 + NO are not observed in the gas phase, possibly due to low volatility; constraints for their branching ratios are instead derived by mass balance. We also measure secondary organic aerosol mass yields from 1,2-DHI (0–23%) and show that oxidation in the presence of aqueous particles leads to formic and acetic acid production. Finally, we incorporate results into GEOS-Chem, a global chemical transport model, to compute the global production (25.3 Tg a–1) and gas-phase loss (20.2 Tg a–1) of 1,2-DHI and show that its oxidation provides non-negligible contributions to the atmospheric budgets of hydroxyacetone, glycolaldehyde, hydroxymethyl hydroperoxide, formic acid, and DHMP.
|ID||Name||Start date||Experiment Category||Reaction Type||Reactant(s)||Oxidant Name||Temperature||Humidity||Type of Seed||RO2 Main Fate||Data Sets (count)||Actions|
|824||Kelvin's lab_20220114_2-Methylbut-3-ene-1,2-diol/Hydrogen peroxide/Ammonium sulfate_Hydroxyl radical_Ammonium sulfate_RH50||2022-01-14||Gas phase chemical reaction, Aerosol formation||Photooxidation||2-Methylbut-3-ene-1,2-diol, Hydrogen peroxide, Ammonium sulfate||Hydroxyl radical||22||50||Ammonium sulfate||HO2||1|