水簇(H2O)n(n=1～5)在过氧自由基大气化学反应中的催化机制研究

The catalysis of water clusters (H2O)n (n=1～5) in the atmospheric chemical reaction of peroxy radicals AO2 (A=H, CH3, C2H5, …) is closely related to various environmental problems such as climate change, acid rain formation and imbalance in global atmospheric nitrogen cycle. The current study focuses on some major relevant scientific problems existing in the atmospheric reaction of water clusters (H2O)n (n=1～5) catalyzing the AO2. These scientific problems include insufficient understanding of the catalytic mechanism, ambiguous understanding of the hydrogen transfer and lack of knowledge about the practical application of the process. In the present study, we have been conducted to study the thermodynamics, kinetics and the reaction mechanism of reaction involving various AO2 and catalyzed by the water clusters (H2O)n (n=1～5). The reaction model for the water clusters (H2O)n (n=1～5) influencing the reactions between AO2 and the important atmospheric species (including SO2, NO, SO3, H2COO, O3, OH, Cl, ClO and HS) is constructed by applying and implanting CP2K open source program with different kinds of quantum chemical calculation methods. The effects of various factors such as the amount, participation type and the action mode of water molecules on AO2 atmospheric reactions have systematically been studied through constructing the relevant potential energy surface, calculating the corresponding rate constant and analyzing the chemical bonding properties of the stationary point species. The study is helpful in understanding the catalytic mechanism of water clusters (H2O)n (n=1～5) during the reaction between AO2 and the important atmospheric species. The study summarizes the rules of superior hydrogen transfer, predicts the influence of water clusters (H2O)n (n=1～5) on AO2 atmospheric reaction in the troposphere environment, and provides scientific basis for reducing the haze pollution and improving the atmospheric environmental quality.

水簇(H2O)n (n=1～5)在过氧自由基AO2 (A=H, CH3, C2H5, •••)大气化学反应中的催化作用，与气候变化、酸雨形成、大气氮化合物循环等环境问题密切相关。针对水簇(H2O)n (n=1～5)催化AO2大气反应中存在的催化机理较缺乏、优势氢转移规律不清楚、未与实际大气环境相关联等基本问题，本项目拟通过CP2K从头算模拟并结合各类量子化学计算方法构建水簇(H2O)n (n=1～5)影响AO2与SO2、NO、SO3、H2COO、O3、OH、Cl、ClO和HS等重要大气物种的反应模型。在此基础上，拟通过构建相关反应势能面、计算对应速率常数及分析驻点物种的化学成键性质，系统深入地研究水分子的数目、参与类型、作用方式等因素对AO2大气反应的影响。期望本项目研究能够解决水簇催化AO2大气反应研究中遇到的上述基本科学问题，为减少大气雾霾污染、改善大气环境质量提供科学依据。

本项目按原计划书设定的研究目标执行，完成了全部预定目标。本项目详细研究了水簇(H2O)n (n = 1-5)在过氧自由基HO2与SO2、SO3、NO、NH2、H2COO、O3、OH、Cl、ClO和HS等10个重要的大气反应机理和动力学性质，并根据相关研究结果对水分子催化有机过氧化物在大气化学反应机理进行了系统阐述。大气化学中水簇(H2O)n (n = 1-5)的催化机理大致可以归纳为两个方面的内容：(1)水分子存在下是否起显著作用，与水分子的参与类型、作用方式、一步或多步反应机制以及水分子数目密切相关；(2)通过与其他物种形成氢键相互作用，水分子参与有助于稳定的氢键网络水合物和环状结构过渡态的形成。项目执行期间研究成果先后在Phys. Chem. Chem. Phys., RSC Adv., Mol. Phys., Comput. Theor. Chem., Chem. J. Chinese Univ., Mol. Simul., Struct. Chem.等期刊发表SCI学术论文13篇，提交会议论文5篇，参加学术会议6人次，培养硕士研究生5人，毕业3人。