所属組織 |
先端科学高等研究院 |
職名 |
特任教員(准教授) |
学歴 【 表示 / 非表示 】
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2007年4月-2010年3月
横浜国立大学 工学府 システム統合工学専攻 博士課程 修了
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2007年4月-2010年3月
横浜国立大学 工学府 システム統合工学専攻 卒業
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2003年4月-2005年3月
横浜国立大学 工学府 機能発現工学専攻 修士課程(博士前期課程) 修了
学内所属歴 【 表示 / 非表示 】
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2020年4月-現在
専任 横浜国立大学 先端科学高等研究院 特任教員(准教授)
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2017年7月-2020年3月
専任 横浜国立大学 先端科学高等研究院 特任教員(助教)
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2016年11月-2017年6月
専任 横浜国立大学 大学院工学研究院 機能の創生部門 特任教員(助教)
論文 【 表示 / 非表示 】
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A Novel Evaluation Method of Powder Electrocatalyst for Gas Evolution Reaction
Nagasawa Kensaku, Matsuura Issei, Kuroda Yoshiyuki, Mitsushima Shigenori
ELECTROCHEMISTRY 90 ( 1 ) 017012 - 017012 2022年
DOI Web of Science CiNii Research
記述言語:日本語 掲載種別:研究論文(学術雑誌) 出版者・発行元:公益社団法人 電気化学会 共著
<p>The evaluation of the powder catalyst activity is essential for the development of high-performance electrocatalysts for water electrolysis. However, the gas generated therein interferes with the accurate measurement by covering the catalyst surface. In this study, we have developed a new evaluation method for a powder oxide electrocatalyst using an alkaline electrolyte. This measurement and analysis method can obtain the intrinsic catalyst activity with no influence from the generation of bubbles. To establish this method, the electrolyzer for evaluation adopts the interdigit flow field for the <i>forced-flow method</i>, and the two methods, namely <i>time zero analysis</i> and <i>flow rate infinitization analysis</i>, were demonstrated by the extrapolation of the measurement data. As a result, the combination of <i>forced-flow method</i> and <i>time-zero analysis</i> is the best evaluation method for the determination of kinetic current at time zero as the equivalent of the no-generation gas condition.</p>
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Corrosion-resistant non-noble metal electrodes for PEM-type water electrolyzer
Tajuddin Aimi Asilah Haji, Elumalai Ganesan, Xi Zeyu, Hu Kailong, Jeong Samuel, Nagasawa Kensaku, F … 全著者表示
Tajuddin Aimi Asilah Haji, Elumalai Ganesan, Xi Zeyu, Hu Kailong, Jeong Samuel, Nagasawa Kensaku, Fujita Jun-ichi, Sone Yoshitsugu, Ito Yoshikazu 閉じる
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 46 ( 78 ) 38603 - 38611 2021年11月
記述言語:日本語 掲載種別:研究論文(学術雑誌) 共著
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Design and characterization of compact proton exchange membrane water electrolyzer for component evaluation test
Nagasawa Kensaku, Ishida Taiki, Kashiwagi Hayato, Sano Yosuke, Mitsushima Shigenori
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 46 ( 74 ) 36619 - 36628 2021年10月
記述言語:日本語 掲載種別:研究論文(学術雑誌) 共著
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Abdel Haleem Ashraf, Nagasawa Kensaku, Kuroda Yoshiyuki, Nishiki Yoshinori, Zaenal Awaludin, Mitsus … 全著者表示
Abdel Haleem Ashraf, Nagasawa Kensaku, Kuroda Yoshiyuki, Nishiki Yoshinori, Zaenal Awaludin, Mitsushima Shigenori 閉じる
ELECTROCHEMISTRY 89 ( 2 ) 186 - 191 2021年 [査読有り]
DOI Web of Science CiNii Research
記述言語:日本語 掲載種別:研究論文(学術雑誌) 出版者・発行元:公益社団法人 電気化学会 共著
<p>For electrocatalysts of oxygen evolution reaction (OER), a new accelerated durability test (ADT) protocol is presented. The protocol is designed to closely mimic the fluctuations of renewable energies. The unit cycle of the current ADT protocol represents the "ON/OFF" operation mode. In the "ON" step, the electrolyzer operates under a DC current of 0.6 A cm<sup>−2</sup>. In the "OFF" step, the electrocatalyst is subjected to a constant potential that is clearly more cathodic than its OER onset potential (namely, 0.3, 0.5, and 0.7 V vs. RHE) for 10 or 60 s. The transition from the "ON" state to the "OFF" state occurs through a cathodic linear sweep voltammetry of a fast sweep rate to mimic the sudden changes in the renewable power. A NiCoO<i><sub>x</sub></i>/Ni-mesh electrode was used as a case study. The electrode showed remarkable durability under continuous operation (<i>i</i> = 0.6 A cm<sup>−2</sup>) for about 900 hours. However, it did suffer severe degradation after a certain number of ADT cycles, and the rate of degradation mainly depends on the potential value and the duration of the "OFF" step. Interestingly, the inclusion of the 10-sec open-circuit potential step after the "ON" step clearly mitigates the impact of energy fluctuations on the durability of OER electrocatalysts.</p>
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Current Measurement and Electrochemical Characterization of Gas Evolution Reactions on a Rotating Ring-Disk Electrode
Bao Yun, Nagasawa Kensaku, Kuroda Yoshiyuki, Mitsushima Shigenori
ELECTROCATALYSIS 11 ( 3 ) 301 - 308 2020年5月 [査読有り]
記述言語:日本語 掲載種別:研究論文(学術雑誌) 共著