2022 Fiscal Year Annual Research Report
二機能性電極の相乗効果による電気化学的バイオマス再生と水素製造
| Project/Area Number |
22F31328
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| Allocation Type | Single-year Grants |
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| Research Institution | Kyoto University |
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Principal Investigator |
北川 宏 京都大学, 理学研究科, 教授 (90234244)
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| Co-Investigator(Kenkyū-buntansha) |
DENG XIAOHUI 京都大学, 理学研究科, 外国人特別研究員
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| Project Period (FY) |
2022-07-27 – 2024-03-31
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| Keywords | nanoparticle / high-entropy alloy / electrochemistry |
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| Outline of Annual Research Achievements |
High-entropy alloy nanoparticles consisting of Pd, Ru, Ni, Co and Cu have been prepared by hot injection of metal precursors into oleylamine at 320 degrees C. The XRD pattern shows FCC phase while the STEM images show the heterogenous distribution of PdCu and RuNiCo in one single nanoparticle. This might be due to the different reduction speeds of metal precursors.
High-entropy selenide of platinum-group metals has been prepared by hot injection of metal precursors into trimethylene glycol at 230 degrees C with polyvinylpyrrolidone as the surfactant. The XRD pattern shows that the selenide prepared exhibits an amorphous structure and the STEM confirms the absence of ordered crystal lattices. The elemental mapping shows the homogeneous distribution of Ru, Rh, Pd, Ir, Pt and Se in the nanoparticles.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
The applicant has conducted systematic research on the synthesis of high-entropy alloy nanoparticles and high-entropy selenide nanostructures by the hot injection method. The synthesized materials have been characterized by transmission electron microscopy, X-ray fluorescence spectroscopy, and synchrotron-based X-ray absorption spectroscopy. In particular, the high-entropy selenide material shows a unique amorphous structure with the homogeneous distribution of platinum-group metals including Ru, Rh, Pd, Ir, and Pt. The XANES results show the positive valence states of the metals and the EXAFS results demonstrate similar M-Se coordination, which confirms the same chemical environments of elements.
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| Strategy for Future Research Activity |
The synthesized high-entropy materials will be loaded on carbon or oxide supports and the electrochemical activity towards various reactions such as hydrogen evolution reaction, oxygen reduction reaction, oxygen evolution reaction and alcohol oxidation reaction will be investigated. In addition, the electrochemical performance will be compared with monometallic counterparts in order to demonstrate the potential advantage of high-entropy configuration. Annealing treatment will then be applied to obtain crystalline selenides from the transformation of amorphous selenides and the electrochemical performance will be compared accordingly. The crystallization process will be studied by in-situ X-ray diffraction experiments.
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