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|
| Type |
Poster Presentation |
| Area |
Inorganic Chemistry |
| Room No. |
Exhibition Hall 2 |
| Time |
4월 18일 (목요일) 11:00~12:30 |
| Code |
INOR.P-19 |
| Subject |
Advanced Electron Paramagnetic Resonance Studies
of the Manganese Nanocatalysts for Water Oxidation
|
| Authors |
Jin Kim, Sun Hee Kim*
Western Seoul Center, Korea Basic Science Institute, Korea
|
| Abstract |
A tetramanganese-calcium cluster, referred to as the oxygen evolving complex (OEC), embedded in Photosystem II catalytically oxidizes water molecules to produce O2. Inspired to the OEC, manganese oxide nanoparticles have been widely utilized to develop artificial water oxidation catalysts. Understanding characteristics of the manganese active sites is crucial to resolve the mechanism of the water oxidation and the concomitant O–O bond formation. However, the detailed information of the manganese sites at the nanoparticles, such as the local geometry and the electronic structure, has been rarely explored. In this presentation we will report the EPR (Electron Paramagnetic Resonance) analyses of the manganese oxide nanoparticles possessing catalytic activity toward water molecules. Electrochemical water oxidation mediated by the nanocatalyst was monitored by the CW EPR spectroscopy, and results revealed the change of the spin state of the manganese ions from the high-spin (S = 5/2) Mn(II) to the low-spin (S = 1/2) Mn(IV). The local geometry and the coordination modes at the particle surface could be estimated from the multi-frequency pulse EPR experiments including ENDOR (Electron-Nuclear DOuble Resonance) and ESEEM (Electron Spin-Echo Envelope Modulation) spectroscopies. Detailed characterizations of these manganese species will be discussed. |
| E-mail |
vyshgorod@hanmail.net |
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123rd General Meeting of the KCS