Publication: Gas-phase oxidation rates and products of 1,2-dihydroxy isoprene

Publication - Gas-phase oxidation rates and products of 1,2-dihydroxy isoprene

Title: Gas-phase oxidation rates and products of 1,2-dihydroxy isoprene
DOI: 10.1021/acs.est.1c04177
Publication Year: 2021
Author list: Kelvin H. Bates, James D. Cope, Tran B. Nguyen
Journal Short Name: Environ. Sci. Technol.
Publisher: American Chemical Society

1,2-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.

Additional Notes

Experiments (2)

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 Download