在水中微滴的表面由臭氧氧氧化
Alexander M Prophet1,2, Kritanjan Polley1,2, Gary J Van Berkel3
1Chemical Sciences Division, Lawrence Berkeley National Laboratory Berkeley CA 94720 USA krwilson@lbl.gov.
Chemical science
|January 5, 2024
概括
在海洋表面,化物与臭氧之间的反应取决于pH值,影响海洋臭氧预算. 这项研究量化了空气-水界面动力学,揭示了对反应气体排放的关键见解.
科学领域:
- 大气化学 大气化学
- 化学动力学 化学动力学
- 海洋与大气层的相互作用
背景情况:
- (I-) 的臭氧 (O3) 氧化发生在海面和海喷气气溶中.
- 这一过程影响了海洋边界层的臭氧预算,并释放出反应性素气体.
- 由于多相运动的复杂性,很难量化精确的表面机制.
研究的目的:
- 为了阐明依赖于pH值的氧化动力学,在空气-水界面的臭氧氧化.
- 了解微滴表面的合扩散,反应和蒸发路径.
- 为了确定化物溶液上臭氧的反应性吸收系数.
主要方法:
- 在四极电动力学陷中利用单个悬浮的微滴.
- 使用一个开放端口采样接口用于质谱测量,以测量反应动力学.
- 开发了一种由空气-水界面上的臭氧动态分子模拟所限制的运动模型.
主要成果:
- 观察到反应途径对散装溶液pH的强烈依赖.
- 在酸性条件下确定了气相臭氧扩散限制,在基本条件下确定了表面反应限制.
- 建议形成一种反应性中间体,IOOO-,类似于化物与臭氧的反应.
- 臭氧的反应吸收系数从4 × 10^-4增加到2 × 10^-3,因为pH从13降低到3.
结论:
- 该研究提供了对空气-水界面上的化物-臭氧反应机制的定量理解.
- pH的依赖性和识别的中间体为海洋大气化学模型提供了关键数据.
- 计算了臭氧的吸收系数,显示了pH的弱缩放,并提供了对反应剂度依赖性的见解.
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