金属纳米颗粒的氧化机制一直是材料与化学领域的研究热点，由于缺少合适的研究手段，目前在大气压环境下对金属颗粒氧化动态过程的认识非常有限。申请人独辟蹊径，利用课题组建立起来的先进环境电镜手段，拟在原子尺度原位研究大气压条件下金属纳米颗粒的氧化过程，通过对氧化过程中的界面演变、形貌结构演变的尺寸效应等对温度和气压等的依赖性的系统研究，考察氧化过程中离子的形成、颗粒内部的应力状况变化、晶界和位错等晶体结构缺陷的产生与运动，获得相应离子的扩散途径和相关的动力学/热力学参数，实现金属纳米粒子的氧化行为可视化。并结合理论模拟，深入揭示金属纳米粒子的氧化机理和柯肯达尔效应的本质，为金属/金属氧化物纳米在催化、能源、微电子、生物医学等领域的应用提供理论与实验支持。

The oxidation mechanism of metal nanoparticles has always been a research hotspot in the field of materials and chemistry. Due to the lack of suitable research methods, the current understanding of metal oxidation under atmospheric pressure is limited. By using the advanced environmental electron microscopy established by our group, applicants are aiming to in situ study the oxidation process of metal nanoparticles under atmospheric pressure at the atomic scale. Through the studies of the interface evolution during the oxidation process, and the dependence of size effect of the morphology evolution on the temperature and pressure, etc., we will investigate the formation of ions during oxidation, the change of stress state inside the particles, the generation and movement of crystal structure defects such as grain boundaries and dislocations, and the diffusion pathways of related ions and related Kinetic/thermodynamic parameters, in order to achieve the visualization of the oxidation behavior of metal nanoparticles. Combined with theoretical simulations, the oxidation mechanism of metal nanoparticles and the nature of the Kirkendall effect will be revealed. This project will provide theoretical and experimental supports for metal/metal oxide nanotechnology applications in the fields of catalysis, energy, microelectronics, and biomedicine.