氧化钇稳定氧化锆上薄膜铂电极中通过晶界传输进行的氧还原。

Oxygen reduction via grain boundary transport in thin film platinum electrodes on yttria stabilized zirconia.

作者信息

Huber T M, Opitz A K, Fleig J

机构信息

Vienna University of Technology, Institute of Chemical Technologies and Analytics, Research Division Electrochemistry, Getreidemarkt 9/164-EC, 1060 Wien, Austria.

出版信息

Solid State Ion. 2015 May;273:8-12. doi: 10.1016/j.ssi.2014.11.006.

DOI:10.1016/j.ssi.2014.11.006

PMID:27570331

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4986289/

Abstract

Model-type sputter deposited platinum microelectrodes with different grain sizes were investigated on single crystalline yttria stabilized zirconia (YSZ) by means of impedance spectroscopy. Measurements on single platinum microelectrodes could be continuously performed for > 100 h and from 250 to 800 °C without losing contact. From the temperature dependence, two parallel reaction pathways for oxygen reduction could be identified. Above 450 °C, a surface path with a rate determining step located at the three phase boundary is predominant. Its polarization resistance is independent of the Pt grain size and exhibits an activation energy of ca. 1.8 eV. In the low temperature regime (< 450 °C) a bulk path through Pt was verified, with an electrode polarization resistance depending on the Pt grain size. This resistance is only slightly thermally activated and the rate limiting step is most probably oxygen diffusion along Pt grain boundaries.

摘要

通过阻抗谱研究了在单晶钇稳定氧化锆（YSZ）上具有不同晶粒尺寸的模型型溅射沉积铂微电极。对单个铂微电极的测量可以在250至800°C的温度下连续进行超过100小时而不会失去接触。从温度依赖性可以确定氧还原的两条平行反应途径。在450°C以上，以位于三相边界处的速率决定步骤的表面路径为主导。其极化电阻与Pt晶粒尺寸无关，并且表现出约1.8 eV的活化能。在低温范围（<450°C）中，验证了通过Pt的体相路径，电极极化电阻取决于Pt晶粒尺寸。该电阻仅略微受热激活，限速步骤很可能是氧沿Pt晶界的扩散。