The reaction between HgBr and O 3 : kinetic study and atmospheric implications.

Autor: Gómez Martín JC; Instituto de Astrofísica de Andalucía, CSIC, 18008, Granada, Spain. jcgomez@iaa.es., Lewis TR; Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain. a.saiz@csic.es.; School of Chemistry, University of Leeds, LS2 9JT Leeds, UK., Douglas KM; School of Chemistry, University of Leeds, LS2 9JT Leeds, UK., Blitz MA; School of Chemistry, University of Leeds, LS2 9JT Leeds, UK., Saiz-Lopez A; Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain. a.saiz@csic.es., Plane JMC; School of Chemistry, University of Leeds, LS2 9JT Leeds, UK.
Jazyk: angličtina
Zdroj: Physical chemistry chemical physics : PCCP [Phys Chem Chem Phys] 2022 May 25; Vol. 24 (20), pp. 12419-12432. Date of Electronic Publication: 2022 May 25.
DOI: 10.1039/d2cp00754a
Abstrakt: The rate constants of many reactions currently considered to be important in the atmospheric chemistry of mercury remain to be measured in the laboratory. Here we report the first experimental determination of the rate constant of the gas-phase reaction between the HgBr radical and ozone, for which a value at room temperature of k (HgBr + O 3 ) = (7.5 ± 0.6) × 10 -11 cm 3 molecule s -1 (1 σ ) has been obtained. The rate constants of two reduction side reactions were concurrently determined: k (HgBr + O) = (5.3 ± 0.4) × 10 -11 cm 3 molecule s -1 and k (HgBrO + O) = (9.1 ± 0.6) × 10 -11 cm 3 molecule s -1 . The value of k (HgBr + O 3 ) is slightly lower than the collision number, confirming the absence of a significant energy barrier. Considering the abundance of ozone in the troposphere, our experimental rate constant supports recent modelling results suggesting that the main atmospheric fate of HgBr is reaction with ozone to form BrHgO.
Databáze: MEDLINE
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