2020 Fiscal Year Final Research Report
Dynamical observation of hydrogen absorption by XAFS-XRD
| Project/Area Number |
18K04682
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 26010:Metallic material properties-related
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| Research Institution | Kyushu University |
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Principal Investigator |
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Keywords | 水素吸蔵 / X線吸収分光 / X線回折 / Pd |
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| Outline of Final Research Achievements |
High capacity of hydrogen absorption in palladium has been reported more than a hundred years before. However, on the hydrogen absorption process, their relations between lattice expansion and electronic structure have not been fully revealed. In this study, we performed XRD and Pd L3-edge XAFS to observe palladium lattice expansion and electronic structure, respectively, in hydrogen atmosphere. To carried out in situ x-ray measurements, we have designed and built a reaction sample cell. We prepared thin film samples with 500 nm thick and nano-particle (NPs) samples with 10 nm. In the process of increasing hydrogen pressure, XRD profile showed lattice expansion due to the hydrogen absorption. On the other hands, the XAFS spectra showed shift to higher energy and a new peak, which indicated formation of bonds between palladium and hydrogen, on hydrogen loading process. Moreover, XRD profile and XAFS spectra showed hysteresis behavior depending on loading and unloading of hydrogen.
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| Free Research Field |
材料工学
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| Academic Significance and Societal Importance of the Research Achievements |
持続可能型社会の構築に向け，水素エネルギーの活用が注目されている．水素エネルギーの利用には水素貯蔵技術の進展が欠かせない状況にある．高い水素/金属比を示すことが広く知られているPdについてその水素吸蔵過程での格子変化と電子状態変化の関係を観察できたことは，他の材料の水素吸蔵能について検討する際に有効である．さらに本研究で新たに開発・製作した試料セルは他の材料の水素吸蔵過程での構造変化を観察することが可能であり，波及効果は非常に大きい．
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