报告人简介：

Bilge Yildiz是麻省理工学院副教授，同时兼任帝国理工学院（Imperial College）和九州大学（Kyushu University）访问副教授。曾获得美国自然基金会杰出青年奖励（NSF CAREER Award），以及电化学领域知名的ECS Charles W. Tobias 杰出青年研究者奖励。Bilge Yildiz已在国际重要学术期刊发表论文数十篇，其中包括Nature Materials，Nano Letters，Journal of the American Chemical Society，Nature Communications等顶级期刊。Bilge Yildiz 主要研究基于固态离子/电子材料的新一代高效的信息处理和能源转换装置的材料系统的理论证明和科学基础，在氧还原反应和离子固态表面氧化动力学方面展开了大量工作。Bilge Yildiz结合表面电子结构、缺陷修饰、组成成分的理论计算和实验数据分析，揭示了弹性应力、变位、温度、氧分压对离子/电子混合材料的影响。

 

报告内容：

A broad range of highly active doped ternary oxides, including perovskites, are desirable materials in electrochemical energy conversion, catalysis and information processing applications. At elevated temperatures related to synthesis or operation, however, the sructure and chemistry of their surfaces can deviate from the bulk. This can give rise to large variations in the kinetics of reactions taking place at their surfaces, including oxygen reduction, oxygen evolution, and splitting of H₂O and CO₂. In particular, aliovalent dopants introduced for improving the electronic and ionic conductivity enrich and phase separate at the surface perovskide oxides. This gives rise to detrimental effects on surface reaction kinetics in energy conversion devices such as fuel cells, electrolyzers and thermochemical H₂O and CO₂ splitting. This talk will have three parts. First, the mechanisms behind such near-surface chemical evolution will be discussed. Second, the dependence of surface chemistry on environmental conditions, including temperature, gas composition, electrochemical potential and crystal orientation will be described. Third, modifications of the surface chemistry that improve electrochemical stability and actvity, designed based on the governing mechanisms, will be presented. Guidelines for enabling high performance perovskite oxides in energy conversion technologies will be presented.