昼間の大気ハロゲン循環 水相酸素原子化学
Evan Z Dalton1, Erik H Hoffmann2, Thomas Schaefer2
1Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States.
Journal of the American Chemical Society
|July 18, 2023
まとめ
大気中のハロゲンの昼間の出所が明らかになった. 塩化物溶液中の窒素の光分解により,窒素塩化物 (ClNO2) が生成され,大気中のハロゲン循環に関する新しい洞察が得られる.
科学分野:
- 大気化学
- ハロゲンサイクル
- 写真化学
背景:
- ハロゲン原子は 大気中の重要な酸化物質です
- 大気中のハロゲン,特に海塩のエアロゾールからの昼間の源は,ほとんど特定されていません.
- 現在のハロゲン循環の理解は,特定の酸化メカニズムに依存しています.
研究 の 目的:
- 海塩エアロゾールにおけるハライドの光化学的酸化を調査する.
- 大気中のハロゲン物質の 未知の昼間源を特定するためです
- 関連する大気条件下でニトリル塩化物 (ClNO2) の形成経路を明らかにする.
主な方法:
- 塩化水溶液中の窒素の実験光分解
- Cl2,HOCl,ClNO2を含む光分解産物を特定するための化学分析
- 新しい化学経路の影響を評価するために大気モデリング.
主要な成果:
- 塩化物溶液における窒素光分解により,ClNO2,Cl2およびHOClが生成される.
- 窒素光分解によるO ((3P) は,塩素をCl2およびHOClに酸化する.
- Cl2とHOClは窒素と反応してClNO2を形成し,これは新しい経路です.
- このメカニズムは,確立されたOH媒介塩化物の酸化とは異なる.
結論:
- 海塩のエアロゾール中の窒素の光分解は,ClNO2の重要な昼間の源である.
- この新しい化学的経路は 大気中のハロゲン循環の理解を 変えてしまいます
- この発見は,ハロゲン化学に関する現在の大気モデルの再評価を必要とします.
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