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Stability and electrochemical performance of Ni/YSZ pattern anodes in H 2 /H 2 O atmosphere
Author(s) -
Yao Weifang,
Croiset Eric
Publication year - 2015
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.22330
Subject(s) - anode , overpotential , electrochemistry , materials science , polarization (electrochemistry) , yttria stabilized zirconia , limiting , partial pressure , analytical chemistry (journal) , chemical engineering , electrode , chemistry , metallurgy , environmental chemistry , oxygen , ceramic , organic chemistry , cubic zirconia , engineering , mechanical engineering
Thorough understanding of H 2 electrochemical oxidation helps optimize SOFC anode design and improve its performance. However, controversies still exist regarding H 2 electrochemical oxidation. Due to their well‐defined 2‐D structure, Ni/YSZ pattern anodes are ideally suited for reaction kinetic studies. In this study, a systematic study was performed to determine conditions for the stabilization of Ni/YSZ pattern anode performance. Moreover, a comprehensive and reliable dataset of H 2 electrochemical oxidation was obtained under stable test conditions. We found that stabilization of Ni/YSZ pattern anode performance relies on temperature and Ni thickness. Polarization resistance ( R p ) depends on temperature, overpotential, H 2 partial pressure, and TPB length, and it increases with decreasing any of these parameters. R p also depends on H 2 O content. When the pH 2 O is between 3000 Pa (3 % of the total gases) and 30 000–40 000 Pa (30–40 % of the total gases), R p decreases with increasing H 2 O content. However, R p is less affected with further increasing H 2 O content. Charge transfer reactions coupled with H 2 O‐related processes contribute to the rate‐limiting steps for H 2 electro‐oxidation.