TY - JOUR
T1 - Density Functional Theory Study for Ni Diffusion on Ni(111) Surface under Solid Oxide Fuel Cell Operating Condition
AU - Nakao, Kazuhide
AU - Ishimoto, Takayoshi
AU - Koyama, Michihisa
N1 - Funding Information:
This work was supported by CREST, JST and JSPS KAKENHI, Grant-in-Aid for JSPS Fellows, 127877. Activities of INAMORI Frontier Research Center is supported by KYOCERA Corporation. A part of the computation was carried out using the computer facilities at the Research Institute for Information Technology, Kyushu University
Publisher Copyright:
© 2016 American Chemical Society.
PY - 2016/8/4
Y1 - 2016/8/4
N2 - Understanding the sintering mechanism of Ni in a solid oxide fuel cell (SOFC) anode is one of the important issues to discuss the long-term durability of SOFC performance. The sintering behavior of Ni is affected not only by the operating temperature but also by the gas composition in the anode chamber. We analyzed the surface diffusion of a Ni adatom and Ni complexes on the Ni(111) surface under the operating temperature and gas compositions in the anode by using density functional theory. The Ni adatom, Ni-H and Ni-S complexes, which can be formed by H2 and H2S in anode gas, were considered as diffusion species on the Ni surface. It is theoretically confirmed that the formation of a NiS complex influences the sintering behavior of Ni depending on the temperature and the impurity H2S concentration in the fuel. Our calculated results are compared with the experimental observation on Ni sintering under various temperatures and H2S concentrations to find a good agreement. We clearly showed the important effect of gas composition in the anode on the sintering properties of Ni in the SOFC anode.
AB - Understanding the sintering mechanism of Ni in a solid oxide fuel cell (SOFC) anode is one of the important issues to discuss the long-term durability of SOFC performance. The sintering behavior of Ni is affected not only by the operating temperature but also by the gas composition in the anode chamber. We analyzed the surface diffusion of a Ni adatom and Ni complexes on the Ni(111) surface under the operating temperature and gas compositions in the anode by using density functional theory. The Ni adatom, Ni-H and Ni-S complexes, which can be formed by H2 and H2S in anode gas, were considered as diffusion species on the Ni surface. It is theoretically confirmed that the formation of a NiS complex influences the sintering behavior of Ni depending on the temperature and the impurity H2S concentration in the fuel. Our calculated results are compared with the experimental observation on Ni sintering under various temperatures and H2S concentrations to find a good agreement. We clearly showed the important effect of gas composition in the anode on the sintering properties of Ni in the SOFC anode.
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U2 - 10.1021/acs.jpcc.6b03440
DO - 10.1021/acs.jpcc.6b03440
M3 - Article
AN - SCOPUS:84980620840
VL - 120
SP - 16641
EP - 16648
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 30
ER -