酸性环境下基于质子耦合电子转移的金属腐蚀动力学研究

A new method to analyze the corrosion kinetics of N80 by proton-coupled electron transfer is proposed in this project. At first, the geometric structure and electronic structure are analyzed on the corrosion interface where single adsorption and co-adsorption of particles occur. It is quite helpful to know the single adsorption and co-adsorption characteristics of different particles on the metal interface. It is expected to understand the impacts of adsorption structure on the geometry and electronic structure in detail. An electronic structure model is developed to describe the complex state quantitatively. Then multiple interactions between the electron orbitals of the oxide film and the electron donor or acceptor in solution will be analyzed from the atomic and molecular scale through the distribution of oxidant and reductant at the interface of oxide film. The interactions analysis can provide the proton-coupled electron transfer and quantitatively describe the proton-coupled electron transfer processes in different pKa solution. Finally, the possible adsorption intermediates and reaction paths in the interface of corrosion were determined by the transition state search analysis. This analysis helps develop the reaction kinetics model during whole corrosion process and determine the key step of corrosion kinetics. With the profound theoretical analysis and experimental research of the corrosion in acidic environment, the dynamic nature of corrosion on the atomic scale was obtained as well as an important theoretical basis for the corrosion protection of chemical equipment was provided.

本项目提出了利用质子耦合电子转移分析N80腐蚀动力学的新思路。首先对腐蚀界面单吸附和共吸附的几何结构和电子结构进行分析，解析界面对不同粒子的吸附和共吸附特性，详细了解吸附结构对界面几何结构和电子结构的影响，建立定量描述复杂状态的电子结构模型；然后通过氧化剂和还原剂在氧化膜界面处的分布规律，从原子尺度上认识界面处各物质的电子轨道与腐蚀溶液中的电子给体或受体的电子轨道间的相互作用从而揭示腐蚀过程中的质子耦合电子转移现象，定量的描述不同pKa溶液中的质子耦合电子转移过程；进而利用过渡态搜索分析，确定界面腐蚀反应中可能的吸附中间态和反应路径, 定量描述由反应物到产物转化过程中各中间步骤的反应动力学模型，确定腐蚀动力学的关键步骤。用该方法对设备在酸性环境下的腐蚀开展系统的理论分析与实验研究，可以从原子尺度揭示腐蚀动力学本质，为化工设备的腐蚀防护提供理论依据。

本项目提出了利用质子耦合电子转移分析N80腐蚀动力学的新思路。首先对腐蚀界面单吸附和共吸附的几何结构和电子结构进行分析，解析界面对不同粒子的吸附和共吸附特性，详细了解吸附结构对界面几何结构和电子结构的影响，建立定量描述复杂状态的电子结构模型；然后通过氧化剂和还原剂在氧化膜界面处的分布规律，从原子尺度上认识界面处各物质的电子轨道与腐蚀溶液中的电子给体或受体的电子轨道间的相互作用从而揭示腐蚀过程中的质子耦合电子转移现象，定量的描述不同pKa溶液中的质子耦合电子转移过程；进而利用过渡态搜索分析，确定界面腐蚀反应中可能的吸附中间态和反应路径, 定量描述由反应物到产物转化过程中各中间步骤的反应动力学模型，确定腐蚀动力学的关键步骤。用该方法对设备在酸性环境下的腐蚀开展系统的理论分析与实验研究，可以从原子尺度揭示腐蚀动力学本质，为化工设备的腐蚀防护提供理论依据。