Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2019 Jun 18;9(33):18971-18977.
doi: 10.1039/c9ra02457c. eCollection 2019 Jun 14.

Mechanism and kinetic study of the reaction of benzoic acid with OH, NO3 and SO4 - radicals in the atmosphere

Xianghe Zhang  1 , Chenxi Zhang  2 , Xiaomin Sun  1 , Jiaoxue Yang  1 , Chen Zhu  3
Affiliations

Mechanism and kinetic study of the reaction of benzoic acid with OH, NO3 and SO4 - radicals in the atmosphere

Xianghe Zhang et al. RSC Adv. .

Abstract

Benzoic acid (BA) is one of the most common organic acids in the Earth's atmosphere and an important component of atmospheric aerosol particles. The reaction mechanism of OH, NO3 and SO4 - radicals with BA in atmospheric water droplets and that of OH radicals with BA in the atmosphere were studied in this paper. The results show that in atmospheric water droplets the potential barriers of the elementary addition reactions of BA with OH radicals are lower than those of elementary abstraction reactions, and the potential barriers of OH-initiated reactions are less than for NO3 and SO4 - reactions. The initiation reactions of OH radicals and BA are exothermic, but the abstraction reactions of NO3 and SO4 - are endothermic processes. Among the products, 6-hydroxybenzoic acid (6-HBA) and 4,6-dihydroxybenzoic acid (4,6-DHBA) are the most stable, while 3-hydroxybenzoic acid (3-HBA) and 3,5-dihydroxybenzoic acid (3,5-DHBA) are much less stable and, thus, much less abundant compared to 6-HBA and 4,6-DHBA. The initiation and subsequent degradation of BA with OH radicals in the gas phase were calculated. The products of addition and abstraction reactions of BA with OH radicals can be further oxidized and degraded by O2/NO. According to the results of kinetic calculations, the total reaction rate constant of OH radicals with BA at 298.15 K in atmospheric water droplets is 2.35 × 10-11 cm3 per molecule per s. The relationship between reaction rate constants, temperature and altitude were also investigated and discussed in the present study.

PubMed Disclaimer

Conflict of interest statement

There are no conflicts to declare.

Figures

Fig. 1
Fig. 1. Reaction pathways for the abstraction and addition reaction of BA with OH radicals in atmospheric water droplets.
Fig. 2
Fig. 2. Reaction pathways for the addition and abstraction reaction of BA with OH radicals in atmospheric water droplets.
Fig. 3
Fig. 3. The products of dihydroxybenzoic acid.
Fig. 4
Fig. 4. Reaction pathways for the abstraction reaction of BA with NO3 radicals in atmospheric water droplets.
Fig. 5
Fig. 5. Reaction pathways for the abstraction reaction of BA with SO4− radicals in atmospheric water droplets.
Fig. 6
Fig. 6. Reaction pathways for the abstraction reaction of BA with OH radicals in the atmosphere.
Fig. 7
Fig. 7. Reaction pathways for the addition reaction of BA with OH radicals in the atmosphere.
Fig. 8
Fig. 8. The relationship between reaction rate constants, temperature and altitude.
See this image and copyright information in PMC

References

    1. Wildermuth M. C. Curr. Opin. Plant Biol. 2006;9:288–296. doi: 10.1016/j.pbi.2006.03.006. - DOI - PubMed
    1. Rogge W. F. Hildemann L. M. Mazurek M. A. Cass G. R. Simoneit B. R. Environ. Sci. Technol. 1993;27:636–651. doi: 10.1021/es00041a007. - DOI - PubMed
    1. Rogge W. F. Hildemann L. M. Mazurek M. A. Cass G. R. Simoneit B. R. Environ. Sci. Technol. 1997;31:2726–2730. doi: 10.1021/es960525k. - DOI - PubMed
    1. Rogge W. F. Hildemann L. M. Mazurek M. A. Cass G. R. Simoneit B. R. Environ. Sci. Technol. 1997;31:2731–2737. doi: 10.1021/es9609563. - DOI - PubMed
    1. Iinuma Y. Herrmann H. J. Chromatogr. A. 2003;1018:105–115. doi: 10.1016/j.chroma.2003.08.028. - DOI - PubMed