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Title: Bulk Migration of Ni/NiO in Ni-YSZ during Reducing Conditions

Abstract

Understanding the migration of Ni/NiO in Ni-YSZ can potentially help to design a better solid oxide fuel cell (SOFC) anode. We have observed that extensive hydrogen reduction and methane steam reforming of Ni-YSZ caused bulk migration of Ni/NiO to at least ~ 5 µm deeper from the Ni-YSZ surface. No significant bulk migration effects were detected after simple thermal treatments in non-reducing/non-reforming environment. Surface analysis of a single zirconia grain in the first 10-20 nm region from annealed, hydrogen reduced and methane steam reformed Ni-YSZ shows Ni-enriched surface supporting earlier claims of Ni exsolution. 3D-EBSD analysis of thermally treated sample before exposing it to reducing and reforming environment indicated mixed NiO/YSZ phase with some porosity and random grain orientation. The surface analysis and mapping were carried out using ToF-SIMS and AES whereas EDS maps on FIB sliced areas on Ni-YSZ were utilized for the bulk analysis. The results provide additional information related to complex reactions occurring in SOFC during internal reforming conditions.

Authors:
; ; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org.:
USDOE
OSTI Identifier:
974936
Report Number(s):
PNNL-SA-64179
Journal ID: ISSN 0013-4651; JESOAN; 26712; KP1704020; TRN: US201007%%895
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of the Electrochemical Society, 157(4):B463-B469; Journal Volume: 157; Journal Issue: 4
Country of Publication:
United States
Language:
English
Subject:
03 NATURAL GAS; 08 HYDROGEN; 30 DIRECT ENERGY CONVERSION; DESIGN; GRAIN ORIENTATION; HYDROGEN; METHANE; POROSITY; SOLID OXIDE FUEL CELLS; STEAM; Grain-sectioning, focused ion beam, Auger electron spectroscopy, methane; Environmental Molecular Sciences Laboratory

Citation Formats

Saraf, Laxmikant V., Baer, Donald R., Lea, Alan S., Zhu, Zihua, Strohm, James J., Sitzman, S. D., and King, David L. Bulk Migration of Ni/NiO in Ni-YSZ during Reducing Conditions. United States: N. p., 2010. Web. doi:10.1149/1.3298442.
Saraf, Laxmikant V., Baer, Donald R., Lea, Alan S., Zhu, Zihua, Strohm, James J., Sitzman, S. D., & King, David L. Bulk Migration of Ni/NiO in Ni-YSZ during Reducing Conditions. United States. doi:10.1149/1.3298442.
Saraf, Laxmikant V., Baer, Donald R., Lea, Alan S., Zhu, Zihua, Strohm, James J., Sitzman, S. D., and King, David L. 2010. "Bulk Migration of Ni/NiO in Ni-YSZ during Reducing Conditions". United States. doi:10.1149/1.3298442.
@article{osti_974936,
title = {Bulk Migration of Ni/NiO in Ni-YSZ during Reducing Conditions},
author = {Saraf, Laxmikant V. and Baer, Donald R. and Lea, Alan S. and Zhu, Zihua and Strohm, James J. and Sitzman, S. D. and King, David L.},
abstractNote = {Understanding the migration of Ni/NiO in Ni-YSZ can potentially help to design a better solid oxide fuel cell (SOFC) anode. We have observed that extensive hydrogen reduction and methane steam reforming of Ni-YSZ caused bulk migration of Ni/NiO to at least ~ 5 µm deeper from the Ni-YSZ surface. No significant bulk migration effects were detected after simple thermal treatments in non-reducing/non-reforming environment. Surface analysis of a single zirconia grain in the first 10-20 nm region from annealed, hydrogen reduced and methane steam reformed Ni-YSZ shows Ni-enriched surface supporting earlier claims of Ni exsolution. 3D-EBSD analysis of thermally treated sample before exposing it to reducing and reforming environment indicated mixed NiO/YSZ phase with some porosity and random grain orientation. The surface analysis and mapping were carried out using ToF-SIMS and AES whereas EDS maps on FIB sliced areas on Ni-YSZ were utilized for the bulk analysis. The results provide additional information related to complex reactions occurring in SOFC during internal reforming conditions.},
doi = {10.1149/1.3298442},
journal = {Journal of the Electrochemical Society, 157(4):B463-B469},
number = 4,
volume = 157,
place = {United States},
year = 2010,
month = 2
}
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