Spontaneous Molecular Bromine Production in Sea‐Salt Aerosols

作者：Yiqun Cao, Zhuo Wang, Jiarong Liu, Qingxin Ma, Shuying Li, Jun Liu, Hao Li, Peng Zhang, Tianzeng Chen, Yonghong Wang, Biwu Chu, Xiuhui Zhang, Alfonso Saiz‐Lopez, Joseph S. Francisco, Hong He · 发表于：Angewandte Chemie International Edition · 年份：2024 · DOI：10.1002/anie.202409779 · 被引用次数：15 · 研究领域：Atmospheric chemistry and aerosols、Air Quality and Health Impacts、Atmospheric Ozone and Climate

Abstract Bromine chemistry is responsible for the catalytic ozone destruction in the atmosphere. The heterogeneous reactions of sea‐salt aerosols are the main abiotic sources of reactive bromine in the atmosphere. Here, we present a novel mechanism for the activation of bromide ions (Br − ) by O 2 and H 2 O in the absence of additional oxidants. The laboratory and theoretical calculation results demonstrated that under dark conditions, Br − , O 2 and H 3 O + could spontaneously generate Br and HO 2 radicals through a proton–electron transfer process at the air–water interface and in the liquid phase. Our results also showed that light and acidity could significantly promote the activation of Br − and the production of Br 2 . The estimated gaseous Br 2 production rate was up to 1.55×10 10 molecules cm −2 ⋅ s −1 under light and acidic conditions; these results showed a significant contribution to the atmospheric reactive bromine budget. The reactive oxygen species (ROS) generated during Br − activation could promote the multiphase oxidation of SO 2 to produce sulfuric acid, while the increase in acidity had a positive feedback effect on Br − activation. Our findings highlight the crucial role of the proton‐electron transfer process in Br 2 production; here, H 3 O + facilitates the activation of Br − by O 2 , serves as a significant source of atmospheric reactive bromine and exerts a profound impact on the atmospheric oxidation capacity.