Oxygen vacancies are important charged defects in oxide ion conductors for oxygen reduction reactions (ORR). They are important reaction sites because of their high oxygen exchange, incorporation ability, and ionic transport reactivity. Herein, to control the defect concentration on the Gd_0.1Ce_0.9O_2-δ (GDC) scaffold, the interface between the electrolyte and the electrode was engineered by a wet-chemical-based infiltration technique which constructed the conformal thin-film-like GDC interlayer (10 nm thickness) with smaller grain size than that of the GDC scaffold. X-ray photoelectron spectroscopy revealed the enriched oxygen vacancies in the infiltrated GDC interlayer with a reduced valence state of Ce. ORR kinetics was substantially improved with the infiltrated GDC interlayer, exhibiting a ∼2-fold decrease in polarization resistance and ∼1.41-fold increase in peak power density (0.072 Ωcm² and ∼780 mW/cm², respectively) at 650 °C. The defect structures at the interfaces and enhanced performance remained unchanged for 200 h at 650 °C.

氧空位是氧还原反应（ORR）中氧化物离子导体中重要的带电缺陷。它们是重要的反应位点，因为它们具有高的氧交换，结合能力和离子迁移反应性。这里，为了控制Gd _0.1 Ce _0.9 O2 _-δ上的缺陷浓度（GDC）支架，通过基于湿化学的渗透技术对电解质和电极之间的界面进行了工程设计，该技术构造出了比GDC支架小的晶粒形的保形薄膜状GDC中间层（厚度为10 nm） 。X射线光电子能谱显示渗透的GDC中间层中富集的氧空位，Ce价态降低。ORR动力学基本上与渗透GDC夹层改善，表现出极化电阻和在峰值功率密度（0.072Ωcm以下~1.41倍增加一个〜2倍的降低²和~780毫瓦/厘米²，分别地）在650℃下。界面处的缺陷结构和增强的性能在650°C下保持200 h不变。