1994 Fiscal Year Final Research Report Summary
Studies on synthesis of mixed ion conducting ceramics and their applications
| Project/Area Number |
05453084
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Structural/Functional materials
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| Research Institution | Nagoya University |
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Principal Investigator |
IWAHARA Hiroyasu School of Eng., Nagoya Univ.Professor, 工学部, 教授 (80023125)
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| Co-Investigator(Kenkyū-buntansha) |
HIBINO Takashi Government Industrial Research Institute of Nagoya, Senior researcher, 構造プロセス部, 主任研究員 (10238321)
ITOH Hideaki School of Eng., Nagoya Univ., Assoc.Prof., 工学部, 助教授 (60109270)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Ionic conduction / Protonic conduction / Perovskite-type oxide / Membrane reactor / Fuel cell / Chemical cogeneration |
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| Research Abstract |
Perovskite-type oxide solid solutions based on BaCeO_3 were synthesized and their ceramics were studied with respect to their ionic conduction at elevated temperatures. Partial substitution of trivalent cations for Ce in BaCeO_3 made the resultant oxide ceramic a mixed ionic conductor of protons and oxide ions under fuel cell condition (H_2/Air). Change in conductivity with ionic radius r of dopant cation was investigated. It was found that the maximum conductivity lay on about r = 0.90-0.95A and that the contribution of oxide ion conduction to the total ionic conductivity under fuel cell condition became marked as the ionic radius grew larger. When BaCeO_3 is doped with divalent cation, both the protonic and oxide ionic conductivities were observed to decrease. Using a temperature programd water vapor desorption experiment and an electrochemical tracer experiment of hydrogen isotope, it could be clarified that low protonic conductivity of the oxide doped with divalent cation was ascribed to small content of proton and its low mobility compared to those in trivalent doped specimens.
These mixed ionic conductors were verified experimentally to be applied to an electrochemical membrane reactor for ethylene production form ethane, a chemical reactor for C_2-hydrocarbon production from methane and a fuel cell for chemical cogeneration which could produce both chemical products and electric power.
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