2004 Fiscal Year Final Research Report Summary
ANALYSIS ON CORRELATION BETWEEN STRUCTURE OF SPECIES IN ROOM-TEMPERATURE MOLTEN SALTAND MECHANISM OF ELECTRODE REACTION
| Project/Area Number |
15550131
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Functional materials chemistry
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| Research Institution | DOSHISHA UNIVERSITY |
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Principal Investigator |
TASAKA Akimasa DOSHISHA UNIVERSITY, FACULTY OF ENGINEERING, PROFESSOR, 工学部, 教授 (90066275)
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| Co-Investigator(Kenkyū-buntansha) |
INABA Minoru DOSHISHA UNIVERSITY, FACULTY OF ENGINEERING, ASSOCIATE PROFESSOR, 工学部, 助教授 (80243046)
KOHARA Shinji JAPAN SYNCHTORON RADIAT RADIATIO RESEARCH INSTITUTE, RESEARCHER, 放射光研究所, 副主幹研究員
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| Project Period (FY) |
2003 – 2004
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| Keywords | Room-temperature molten salt / Ionic liquid / Tetramethylammonium fluoride / High-energy X-ray diffraction / Analysis of structure of liquid / Electrochemical fluorination / Atmosphere plasma spraying technique / Sol-gel method |
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| Research Abstract |
(CH_3)_4NF・mHF (m=3〜5) and (CH_3)_4NF・mDF (m=3.0, 3.5, 4.0) melts were prepared by reaction of (CH_3)_4NF with HF and DE respectively. Analysis of high-energy X-ray diffraction of (CH_3)_4NF・mHF and NH_4F・nHF melts indicated that (CH_3)_4NF・mHF melts had the intermolecular correlations of the (CH_3)_4N^+ cation in liquid state and hence the tetrahedral NC_4 short-range structure was maintained. Comparison of the measured Raman and IR spectra of (CH_3)_4NF・mHF melts with ab initio calculation revealed that a HF molecule in addition to (FH)F^-, (FT)_2F^-, and (FD)_3F^- existed in the melts and that (FH)_2F^- was the most species among them having HF. The frequencies observed in Raman and IR spectra of (CH_3)_4NF・mDF melts were compared with ab initio calculation. Consequently, it is confirmed that (FD)F^-, (FD)_2F^-, and (FD)_3F^- also existed in the melts. Electrolytic conductivity of (CH_3)_4NF・mHF melts increased with increasing m value, whereas their viscosity decreased with the increase of m value, because the concentration of HF molecule in the melts increased with increasing m value. In electrolysis of (CH_3)_4NF・mHF melts containing CsF with a nickel anode, the best ratio of (CF_3)_3N to the overall anode gas was 40.5%. In electrolysis of only (CH_3)_4NF・mHF melts with the LiNiO_2 and the LaNiO_3 coated Ni sheet anodes prepared by atmosphere plasma spraying technique and sol-gel method, an insulating NiF_2 was prevented from formation in the surface layer on the anodes and resistance of the surface layer was decreased. The best ratio of (CF_3)_3N to the overall anode gas on the LiNiO_2 coated Ni sheet anode prepared by atmosphere plasma spraying technique was 33.1%. Those on the LiNiO_2 and the LaNiO_3 coated Ni sheet anodes prepared by sol-gel method were 27% and 25%, respectively.
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