Atomic structures and oxygen dynamics of CeO2 grain boundaries

Bin Feng, Issei Sugiyama, Hajime Hojo, Hiromichi Ohta, Naoya Shibata, Yuichi Ikuhara

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

Material performance is significantly governed by grain boundaries (GBs), a typical crystal defects inside, which often exhibit unique properties due to the structural and chemical inhomogeneity. Here, it is reported direct atomic scale evidence that oxygen vacancies formed in the GBs can modify the local surface oxygen dynamics in CeO2, a key material for fuel cells. The atomic structures and oxygen vacancy concentrations in individual GBs are obtained by electron microscopy and theoretical calculations at atomic scale. Meanwhile, local GB oxygen reduction reactivity is measured by electrochemical strain microscopy. By combining these techniques, it is demonstrated that the GB electrochemical activities are affected by the oxygen vacancy concentrations, which is, on the other hand, determined by the local structural distortions at the GB core region. These results provide critical understanding of GB properties down to atomic scale, and new perspectives on the development strategies of high performance electrochemical devices for solid oxide fuel cells.

Original languageEnglish
Article number20288
JournalScientific reports
Volume6
DOIs
Publication statusPublished - Feb 3 2016
Externally publishedYes

    Fingerprint

All Science Journal Classification (ASJC) codes

  • General

Cite this

Feng, B., Sugiyama, I., Hojo, H., Ohta, H., Shibata, N., & Ikuhara, Y. (2016). Atomic structures and oxygen dynamics of CeO2 grain boundaries. Scientific reports, 6, [20288]. https://doi.org/10.1038/srep20288