研究課題/領域番号 |
16K18236
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研究機関 | 九州大学 |
研究代表者 |
ドルース ジョン 九州大学, カーボンニュートラル・エネルギー国際研究所, 助教 (50635886)
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研究期間 (年度) |
2016-04-01 – 2018-03-31
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キーワード | Solid oxide electrodes / Oxygen exchange / Surface chemistry |
研究実績の概要 |
Construction of the equipment for annealing under controlled atmospheres is complete. Unanticipated sources of experimental error (e.g. temperature transients) were eliminated by a modified design, improving the accuracy of future measurements. A research stay at Imperial College (Prof. Kilner) has been completed, using the unique facilities to collaborate on next generation electrode materials, and forge stronger links between the two institutions. These experiments, and those at the PI’s home institution, showed that water vapour accelerates oxygen surface exchange, which plateaus at higher humidity. Surface characterisation suggests this is due to poisoning of the surface by impurities transported by the water vapour. Further characterisation of the surface contamination is underway.
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現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
By optimising the experimental set up and protocols, the experiments have proceeded more efficiently than originally anticipated, despite some initial setbacks. Work has already commenced on the experiments proposed for FY2017 (influence of CO2 content), in parallel with the experiments on humidity. The theoretical aspects will now be pursued in FY2017, with a fuller data set available to guide calculations. Please note the PI is currently taking a period of family care leave. To mitigate any impact, much of the laboratory-based experiments and measurement for FY2016 were completed before the leave period started, allowing the numerical modelling and interpretation of these data to be conducted as time permits during the leave of absence.
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今後の研究の推進方策 |
FY2017 will see the completion of surface exchange measurements as a function of atmospheric H2O and CO2 content. This will be extended to investigate the effect of oxygen activity at fixed humidity. The complete dataset will allow theoretical interpretation of the data, combining macroscopic (bulk defect chemistry) and atomistic (DFT) approaches. The extent of the surface poisoning effect (offsetting enhancement by humidification) will be studied by measuring surface exchange kinetics of samples after deliberate contamination. Samples exposed to wet atmospheres showed diffusion of fluorine impurities (arising from the isotopically labelled water). Diffusivities will be extracted, to add to the scant literature data on the typically ignored diffusion of foreign anions in these materials.
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次年度使用額が生じた理由 |
Part of the residual amount is due to the fact that the PI was able to cover travel expenses from other funding (including a Daiwa Adrian award), and it was decided to allocate the funds earmarked for travel expenses to further improve the experimental setup. Also, the PI is currently taking a period of parental care leave from the university, which began before the end of the fiscal year 2016, and thus the budgets cannot be used according to regulations. The spending of the budget was proceeding at the rate as planned, and quotations for certain items were obtained, but could not be delivered before the period of leave began. Once the PI returns from parental leave, these items originally intended to be delivered by end of FY2016 will be ordered.
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次年度使用額の使用計画 |
Part of the residual amount will be spent to add the capability to precisely measure the humidity of the gas stream, and to control this with a new humidification system. The main purchase with the remaining funds with be for isotopically labelled (oxygen-18) carbon dioxide gas, to perform direct isotope exchange measurements with carbon dioxide for validation studies. The remainder of the amount will allocated to cover consumables required for FY2017.
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