Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
The influence of SO2 as the Criegee intermediate scavenger on the heterogeneous oxidation of oleic acid
Abstract As a well-known Criegee intermediate (CI) scavenger, SO2 can react with CIs in the gas phase to form sulphuric acid, which can be further converted to sulfate aerosols, which make an important contribution to haze formation. Despite the potential importance, the interaction of SO2 with the CIs produced by heterogeneous oxidation of unsaturated fatty acids remains largely unclear. In this work, the heterogeneous reactions of oleic acid (OA) thin films with O3 and O3/SO2 mixture gases are studied under four different relative humidities (RHs): 5%, 30%, 60% and 80%, using microscopic Fourier transform infrared (micro-FTIR) spectrometer combined with a gas-flow system. A detailed comparison on formation rates of ester and intensity ratios of 1742 cm−1 band (envelope CO of ester) to 1712 cm−1 band (feature CO of carboxyl) between the two reaction systems shows that the addition of SO2 inhibits the conversion of carboxyl to ester at any RH. As the SO2 concentration increases, the formation rates and final relative amount of ester decrease. Based on these data, it can be concluded that SO2 consumes part condensed-phase CIs produced by ozonolysis of OA, resulting in a significant inhibition in ester formation. The present results provide an important atmospheric implication on the reaction between SO2 and condensed-phase CIs, which may be a missing sulfate production pathway in the atmosphere.
Graphical abstract Display Omitted
Highlights The influence of SO2 on heterogeneous reaction of OA/O3 at different RHs is first explored. SO2 can consume the condensed-phase CIs to inhibit the formation of ester. The condensed-phase CIs can oxidize SO2 to form gas-phase sulphuric acid. This work proposes a new missing sulfate production pathway in the troposphere.
The influence of SO2 as the Criegee intermediate scavenger on the heterogeneous oxidation of oleic acid
Abstract As a well-known Criegee intermediate (CI) scavenger, SO2 can react with CIs in the gas phase to form sulphuric acid, which can be further converted to sulfate aerosols, which make an important contribution to haze formation. Despite the potential importance, the interaction of SO2 with the CIs produced by heterogeneous oxidation of unsaturated fatty acids remains largely unclear. In this work, the heterogeneous reactions of oleic acid (OA) thin films with O3 and O3/SO2 mixture gases are studied under four different relative humidities (RHs): 5%, 30%, 60% and 80%, using microscopic Fourier transform infrared (micro-FTIR) spectrometer combined with a gas-flow system. A detailed comparison on formation rates of ester and intensity ratios of 1742 cm−1 band (envelope CO of ester) to 1712 cm−1 band (feature CO of carboxyl) between the two reaction systems shows that the addition of SO2 inhibits the conversion of carboxyl to ester at any RH. As the SO2 concentration increases, the formation rates and final relative amount of ester decrease. Based on these data, it can be concluded that SO2 consumes part condensed-phase CIs produced by ozonolysis of OA, resulting in a significant inhibition in ester formation. The present results provide an important atmospheric implication on the reaction between SO2 and condensed-phase CIs, which may be a missing sulfate production pathway in the atmosphere.
Graphical abstract Display Omitted
Highlights The influence of SO2 on heterogeneous reaction of OA/O3 at different RHs is first explored. SO2 can consume the condensed-phase CIs to inhibit the formation of ester. The condensed-phase CIs can oxidize SO2 to form gas-phase sulphuric acid. This work proposes a new missing sulfate production pathway in the troposphere.
The influence of SO2 as the Criegee intermediate scavenger on the heterogeneous oxidation of oleic acid
Yang, Miao (Autor:in) / Ma, Shuai-Shuai (Autor:in) / Ashraf, Hamad (Autor:in) / Pang, Shu-Feng (Autor:in) / Zhang, Yun-Hong (Autor:in)
Atmospheric Environment ; 231
22.04.2020
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
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