论文标题
阐明n $ _2 $ o $ $ _5 $ in Aquous Aerosol的反应性吸收机制
Elucidating the mechanism of reactive uptake of N$_2$O$_5$ in aqueous aerosol
论文作者
论文摘要
所有氮氧化物的近三分之一通过反应性吸收n $ _2 $ o $ _5 $从大气中清除，以水溶液中的水溶液。反应性吸收的主要步骤是n $ _2 $ o $ _5 $的快速水解，尽管进行了重大研究，但该过程的机制和速率尚不清楚。在这里，我们使用基于机器学习的反应性许多身体潜力和重要性采样分子动力学模拟的方法来研究N $ _2 $ o $ $ _5 $的溶剂化和后续水解。我们发现，硝酸的水解是通过分子内电荷分离和溶解的协调波动进行的，其特征速率为4.1 ns $^{ - 1} $，比传统假设快的数量级。这个很大的速率将反应性吸收的标准模型提出了问题，该模型设想了气体和大量解决方案之间的局部平衡。我们提出了一个基于界面反应性的替代模型，该模型可以解释现有的实验观察结果，并通过显式模拟证实。
Nearly one third of all nitrogen oxides are removed from the atmosphere through the reactive uptake of N$_2$O$_5$ into aqueous aerosol. The primary step in reactive uptake is the rapid hydrolysis of N$_2$O$_5$, yet despite significant study, the mechanism and rate of this process are unknown. Here we use machine learning-based reactive many body potentials and methods of importance sampling molecular dynamics simulations to study the solvation and subsequent hydrolysis of N$_2$O$_5$. We find that hydrolysis to nitric acid proceeds through the coordinated fluctuation of intramolecular charge separation and solvation, and its characteristic rate is 4.1 ns$^{-1}$, orders of magnitude faster than traditionally assumed. This large rate calls into question standard models of reactive uptake that envision local equilibration between the gas and the bulk solution. We propose an alternative model based on interfacial reactivity that can explain existing experimental observations and is corroborated by explicit simulations.
