A theoretical study on the formation and oxidation mechanism of hydroxyalkylsulfonate in the atmospheric aqueous phase

Danna Zhang; Guochun Lv; Xiaomin Sun; Chenxi Zhang; Zhiqiang Li

doi:10.1039/c9ra05193g

A theoretical study on the formation and oxidation mechanism of hydroxyalkylsulfonate in the atmospheric aqueous phase

RSC Adv. 2019 Aug 30;9(47):27334-27340. doi: 10.1039/c9ra05193g. eCollection 2019 Aug 29.

Authors

Danna Zhang¹, Guochun Lv¹, Xiaomin Sun¹, Chenxi Zhang², Zhiqiang Li³

Affiliations

¹ Environment Research Institute, Shandong University Jinan 250100 China sxmwch@sdu.edu.cn.
² College of Biological and Environmental Engineering, Binzhou University Binzhou 256600 China.
³ Center for Optics Research and Engineering (CORE), Shandong University Qingdao 266237 China lzq@sdu.edu.cn.

Abstract

Hydroxymethanesulfonate (HMS) is an important organosulfur compound in the atmosphere. In this work, we studied the formation mechanism of HMS via the reaction of formaldehyde with dissolved SO₂ using the quantum chemistry calculations. The results show that the barrier (9.7 kcal mol^-1) of the HCHO + HSO₃ ^- reaction is higher than that (1.6 kcal mol^-1) of the HCHO + SO₃ ^2- reaction, indicating that the HCHO + SO₃ ^2- reaction is easier to occur. For comparison, the reaction of acetaldehyde with dissolved SO₂ also was discussed. The barriers for the CH₃CHO + HSO₃ ^- reaction and CH₃CHO + SO₃ ^2- reaction are 16.6 kcal mol^-1, 2.5 kcal mol^-1, respectively. This result suggests that the reactivity of HCHO with dissolved SO₂ is higher than that of CH₃CHO. The further oxidation of CH₂(OH)SO₃ ^- and CH₃CH(OH)SO₃ ^- by an OH radical and O₂ shows that the SO₅˙^- radical can be produced.