Researchers at Tampere University have discovered that sulfur trioxide can form products other than sulfuric acid in the atmosphere by interacting with organic and inorganic acids.
Researchers at Tampere University have discovered that sulfur trioxide can form products other than sulfuric acid in the atmosphere by interacting with organic and inorganic acids. These previously uncharacterized acid sulfuric anhydride products are almost certainly key contributors to atmospheric new particle formation and a way to efficiently incorporate carboxylic acids into atmospheric nanoparticles. Better prediction of aerosol formation can help curb air pollution and reduce uncertainties concerning climate change.
While it’s long been assumed that the sole fate of gaseous SO3 at any reasonable humidity is rapid conversion to sulfuric acid, significant levels of SO3 have recently been shown to accumulate under urban polluted conditions (Yao et al.), indicating gaps in our understanding of its formation and loss processes. The researchers of aerosol physics at Tampere University and their collaborators have now shown that the interplay between SO3 and some of the most ubiquitous acid molecules in the atmosphere leads rapidly to acid sulfuric anhydride molecules, which have all the hallmarks of being very efficient at forming new particles and consequently affecting climate dynamics.
In their work, the researchers employed a combination of laboratory experiments and quantum chemical calculations to examine the reaction products of SO3 with both organic and inorganic acids under ambient relevant conditions of pressure and temperature. Field measurements further validated the relevance of these reactions across diverse chemical environments, including urban areas, marine and polar regions, and volcanic plumes.
Read more at Tampere University
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