Environment Research Institute, Shandong University, Qingdao, 266237, PR China.
Environment Research Institute, Shandong University, Qingdao, 266237, PR China.
Chemosphere. 2020 Aug;252:126292. doi: 10.1016/j.chemosphere.2020.126292. Epub 2020 Feb 25.
New particle formation (NPF) involving amines in the atmosphere is considered an aggregation process, during which stable molecular clusters are formed from amines and sulfuric acid via hydrogen bond interaction. In this work, ab initio dynamics simulations of ammonium bisulfate formation from a series of amines, SO, and HO molecules were carried out in the gas phase and at the air-water interface. The results show that reactions between amines and hydrated SO molecules in the gas phase are barrierless or nearly barrierless processes. The reaction rate is related to the basicity of gas-phase amines-the stronger the basicity, the faster the reaction. Furthermore, SO hydrolysis catalyzed by amines occurs simultaneously with HSO-amine cluster formation. At the air-water interface, reactions between amines and SO involve multiple water molecules. The reaction center's ring structure (amine-SO-nHO) promotes the transfer of protons in the water molecules. The formed ammonium cation (-RNH) and the bisulfate anion (HSO) are present and stable by means of hydrogen bond interaction. The cluster formation mechanism provides new insights into NPF involving amines, which may play an important role in the formation of aerosols in some heavily polluted areas - e.g., those with a high amine concentration.
新粒子形成（NPF）涉及大气中的胺，被认为是一个聚合过程，在这个过程中，胺和硫酸通过氢键相互作用形成稳定的分子簇。在这项工作中，我们在气相和空气-水界面上进行了一系列胺、SO 和 HO 分子形成硫酸氢铵的从头算动力学模拟。结果表明，气相中胺与水合 SO 分子之间的反应是无势或近无势过程。反应速率与气相中胺的碱性有关-碱性越强，反应越快。此外，胺催化的 SO 水解与 HSO-胺簇的形成同时发生。在空气-水界面上，胺与 SO 之间的反应涉及多个水分子。反应中心的环结构（胺-SO-nHO）促进了水分子中质子的转移。形成的铵阳离子（-RNH）和硫酸氢根阴离子（HSO）通过氢键相互作用存在且稳定。该簇形成机制为涉及胺的 NPF 提供了新的见解，这可能在某些污染严重地区（例如胺浓度较高的地区）气溶胶的形成中发挥重要作用。
