核-壳结构纳米颗粒制备及其氧还原催化性能研究

项目名称： 核-壳结构纳米颗粒制备及其氧还原催化性能研究

项目编号： No.51502138

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 一般工业技术

项目作者： 梁凤丽

作者单位： 南京航空航天大学

项目金额： 20万元

中文摘要： 对于中低温固体氧化物燃料电池（SOFC）的研究，阴极材料的活性和稳定性是制约其发展的瓶颈问题。我们之前通过核-壳结构的Ag@CeO2颗粒修饰钙钛矿阴极提高了电极的稳定性，CeO2壳层可以防止Ag颗粒在高温下、长时间操作过程中长大，但是由于催化剂颗粒较大、壳层材料太致密导致电极活性提高不明显。本项目将通过新的合成路径制备多孔壳层包覆的Ag纳米颗粒作为阴极修饰催化剂，使阴极的活性和稳定性都有大幅度提升。通过掺杂适当的离子提高壳层的吸氧、导氧能力，同时采用模板法制备多孔壳层，利于氧气接触Ag颗粒。通过反胶束法合成小于20 nm的核-壳颗粒，将该纳米催化剂浸渍进入多孔钙钛矿骨架形成复合阴极，研究催化剂颗粒在复合阴极中的分布、微观结构与电极活性、稳定性之间的构效关系，阐明氧气在复合电极界面的氧还原反应机理，最终研制出具有高活性、高稳定性的阴极材料，为中低温SOFC的商业化打下坚实的基础。

中文关键词： 固体氧化物燃料电池；阴极材料；电化学催化；核-壳结构；氧还原

英文摘要： For intermediate and low temperature solid oxide fuel cells (SOFC), the activity and stability performance of the cathode materials are bottle-necking issues in the development of SOFC technology. In our previous study, we introduced core-shell structural Ag@CeO2 nanoparticles into the perovskite cathode to improve its thermal stability. The CeO2 shell in the nanoparticles can prevent the aggregation of Ag core working at high temperature for a long time. Novel shell protected Ag core nanoparticles fabrication method is proposed in this project, and the catalysts are expected to show enhanced performance in oxygen reduction reaction (ORR) activity and long-term thermal stability as SOFC cathode decorators. The shell is elements doped-CeO2 with high electrical and ionic conductivity, and SiO2 template is used to form porous shell to benefit the distribution of oxygen on the Ag core. The core-shell particles size is expected to form less than 20 nm by a reverse micelle method in this project, and we will introduce the catalytic particles into a porous structural perovskite backbone by wet impregnation. It is expected that the scientific issues, including the distribution of the catalytic particles on the porous cathode structure, the relationship between the structure and composition of the cathode and the electrochemical performance of the cathode in the application of the core-shell structural particles in SOFC cathode, will be elucidated. Finally a novel high performance and long-term stability cathode will be developed to accelerate the commercialization process of intermediate and low temperature SOFCs.

英文关键词： solid oxide fuel cells;cathode;electrochemical catalysis;core-shell structure;oxygen reduction reaction