Role of Hydroperoxyl Radicals in Heterogeneous Oxidation of Oxygenated Organic Aerosols

• DOI: 10.1021/acs.est.3c09024
• Publication Date: 2024-02-27T14:10:05Z
• Authors: Wen Zhang; Kassem Issa; Tiffany Tang; Haofei Zhang
• Keywords: Hydroperoxyl

Heterogeneous oxidative aging of organic aerosols (OA) occurs ubiquitously in the atmosphere, initiated by oxidants, such as hydroxyl radicals (•OH). Hydroperoxyl (HO2•) are also an important oxidant troposphere, and its gas-phase chemistry has been well studied. However, role HO2• heterogeneous OA oxidation remains elusive. Here, we carry out •OH-initiated several model systems under different conditions a flow tube reactor characterize molecular products using suite mass spectrometry instrumentation. By hydrogen–deuterium exchange (HDX) with thermal desorption iodide-adduct chemical ionization spectrometry, provide direct observation hydroperoxide (ROOH) formation from peroxy (RO2•) reactions for first time. The ROOH may contribute substantially to products, varied parent structure. Furthermore, regulating RO2• reaction pathways, greatly influence overall composition oxidized OA. Last, suggest that + readily occur at particle interface rather than bulk. These findings new mechanistic insights into help fill critical knowledge gap understanding atmospheric aging.