Dual phase oxide membranes have shown promising hydrogen permeation fluxes in syngas applications due to their high mixed proton electron conduction (MPEC). However, the conductivity of grain boundaries can be many orders of magnitude lower than that of the bulk and so limits the total conductivity and hydrogen permeation. In this study, the three‐dimensional nanoscale oxygen and cation distributions around grain and phase boundaries in a BaCe_0.8Y_0.2O_3‐δ‐Ce_0.8Y_0.2O_2‐δ (BCY‐YDC) membrane were quantified by atom probe tomography (APT) and related to average grain boundary conductivity measured by electrochemical impedance spectroscopy (EIS). Segregation varied among the general high‐angle grain boundaries analyzed, but no trend from orientation analysis was determined. Correlative APT and electron energy loss spectroscopy (EELS) of one YDC grain boundary revealed composition and cerium valence information, respectively, allowing for the determination of vacancies at the grain boundary. While a specific MPEC membrane is characterized, the results are relevant to proton and electron conduction in a number of technologically important ceramics.

中文翻译：

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质子-电子混合氧化物复合材料中晶界缺陷化学的定量

由于其高混合质子电子传导（MPEC），双相氧化膜在合成气应用中显示出令人鼓舞的氢渗透通量。但是，晶界的电导率可能比本体的电导率低许多个数量级，因此限制了总电导率和氢渗透。在这项研究中，BaCe _0.8 Y _0.2 O3 _-δ- Ce _0.8 Y _0.2 O2 _-δ中晶粒和相界周围的三维纳米级氧和阳离子分布（BCY-YDC）膜通过原子探针层析成像（APT）进行定量，并与通过电化学阻抗谱（EIS）测量的平均晶界电导率相关。在分析的一般高角度晶界中偏析有所不同，但未确定取向分析的趋势。一个YDC晶界的相关APT和电子能量损失谱（EELS）分别揭示了成分和铈价信息，从而可以确定晶界的空位。尽管对特定的MPEC膜进行了表征，但结果与许多技术上重要的陶瓷中的质子和电子传导有关。