固体氧化物燃料电池表界面介尺度结构上的扩散反应研究

The meso-structures of surface, interface and boundary in solid oxide fuel cell greatly raise the length of three-phase boundary, the efficiencies of electrode materials for transportation of molecule, atom, oxide ion and electron, the uniformity in the macro-scale distributions of various physical fields, reduce the overpotentials from activation polarization, ohmic polarization and diffusion polarization, which greatly increase the electro-catalytic activity and stability of electrodes. On the other hand, the heterogeneity in the meso-structure causes the micro-scale non-uniform distributions of various physical fields, which can promote transportation and reaction molecule, atom, oxide ion and electron as well as the migration of metal ions in electrodes. .In this project, we will investigate the micro-scale distribution of various physical fields on the meso-structure, the transportation and reaction of molecule, atom, oxide ion and electron, study the stability of meso-structure under potential field, and develop new technologies for tuning meso-structures. .The project includes, (1) construction of the models for meso-structures in hierarchical electrodes, (2) dependence of transportation and reaction on meso-structures, (3) relation between micro-scale potential distribution, migration of metal ions and stability of meso-structures, and (4) experimental investigation on the electro-catalytic activity and stability of meso-structures of surface, interface and boundary..The fulfillment of the project will demonstrate the dependence of transportation and reaction on meso-structures, which solidify the fundamentals of chemical engineer for solid oxide fuel cells.

固体氧化物燃料电池的表界面介尺度结构，一方面可提高电极材料的分子/原子/离子/电子扩散效率，提高各种物理场的宏观分布均匀性，提高电极的电催化活性和稳定性；另一方面其组成和结构的不均匀性引起各种物理场微观非均匀分布。本项目从表界面介尺度结构上电势等物理场的微观分布研究入手，研究认识表界面介尺度结构上扩散反应及稳定性，探讨其调控技术。主要研究内容：（1）多级结构电极中的表界面介尺度结构模型构建；（2）表界面介尺度结构与扩散反应的关系；（3）电势分布、金属离子扩散与介尺度结构的稳定性关系；（4）表界面介尺度结构及其电催化性能的实验研究。通过本项目研究，阐明表界面介尺度结构与扩散反应的关系，奠定固体氧化物燃料电池的高电催化活性和高稳定性电极的化工科学基础。

固体氧化物燃料电池的表界面介尺度结构，可提高电极材料的分子/原子/离子/电子扩散效率，提高各种物理场的宏观分布均匀性，提高电极的电催化活性和稳定性。本项目研究认识了表界面介尺度结构上电极反应及稳定性。具体研究建立了微米级LSM-YSZ复合电极表界面介尺度结构的物理模型，研究了多级结构复合电极的构建；认识了复合电极中表界面介尺度结构与电极反应的关系，研究了膜电极接触界面与电极反应的关系，多级结构电极中骨架离子/电子传导率与电极反应的关系，解析CeO2基催化剂上氧还原反应的多个耦合过程，认识了复合电极颗粒尺寸、构筑方式等因素对介尺度结构上的扩散反应影响规律；认识了复合电极中电势分布、金属离子扩散与介尺度结构的稳定性关系；制备出新型表界面介尺度结构电极，研究了新型电极材料的电催化性能和反应机制。通过本项目研究，阐明了表界面介尺度结构与扩散反应的关系，奠定了固体氧化物燃料电池的高电催化活性和高稳定性电极的化工科学基础。