Sulfate formation is dominated by manganese-catalyzed oxidation of SO<sub>2</sub> on aerosol surfaces during haze events.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33790274.
- Also identified by DOI 10.1038/s41467-021-22091-6 and PMC identifier 8012371.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The formation mechanism of aerosol sulfate during wintertime haze events in China is still largely unknown. As companions, SO<sub>2</sub> and transition metals are mainly emitted from coal combustion. Here, we argue that the transition metal-catalyzed oxidation of SO<sub>2</sub> on aerosol surfaces could be the dominant sulfate formation pathway and investigate this hypothesis by integrating chamber experiments, numerical simulations and in-field observations. Our analysis shows that the contribution of the manganese-catalyzed oxidation of SO<sub>2</sub> on aerosol surfaces is approximately one to two orders of magnitude larger than previously known routes, and contributes 69.2% ± 5.0% of the particulate sulfur production during haze events. This formation pathway could explain the missing source of sulfate and improve the understanding of atmospheric chemistry and climate change.