4- 1State Key Joint Laboratory of Regional Environment and Sustainability, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
- 2State Key Laboratory of Coordination Chemistry, Key Laboratory of Mesoscopic Chemistry of Ministry of Education, The Institute of Green Chemistry and Engineering, Nanjing University, Suzhou, Jiangsu 215163, China.
- 3National Key Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
- 4College of Environmental Sciences and Engineering, Center for Environment and Health, Peking University, Beijing 100871, China
Sulfur dioxide (SO2) hydrolysis is a critical step in secondary sulfate formation, which significantly affects air quality and climate change. Since the 1980s, debate has persisted over whether this reaction occurs mainly at the air–water interface or in the bulk phase. In this study, we investigate SO2 hydrolysis in heterogeneous systems using molecular dynamics simulations that are driven by a deep neural network potential with ab initio accuracy. In previous studies, rapid interfacial reactions have been proposed to account for the unexpectedly high SO2 uptake coefficients. In contrast, our results reproduce the observed uptake coefficients but show that interfacial hydrolysis contributes only 1%. We find that hydrolysis is accelerated in the bulk phase, where the denser hydrogen-bond network enhances SO2 electrophilicity and lowers the reaction barrier. The theoretical simulations in this work help to improve the understanding of aqueous sulfate aerosol formation and microdroplet chemistry.
How to cite: Du, M., Yang, M., Wang, H., Song, Y., and Zhu, T.: Bulk Phase Dominates Sulfur Dioxide Hydrolysis over Interfacial Processes, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-2027, https://doi.org/10.5194/egusphere-egu26-2027, 2026.
