Development of Pt-free redox flow fuel cells using polyoxometalates as redox mediators

2022 Fiscal Year Final Research Report

• Project/Area Number: 18H03852
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Medium-sized Section 27:Chemical engineering and related fields
• Research Institution: Kyoto University
• Principal Investigator: Eguchi Koichi 京都大学, 工学研究科, 名誉教授 (00168775)
• Co-Investigator(Kenkyū-buntansha): 城間 純 国立研究開発法人産業技術総合研究所, エネルギー・環境領域, 主任研究員 (00357245) ; 松井 敏明 京都大学, 工学研究科, 准教授 (90378802)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: ポリオキソメタレート / ヘテロポリ酸 / 酸化還元メディエーター / レドックスフロー型PEFC

Outline of Final Research Achievements

In this study, we aimed to develop a Pt-free redox flow polymer electrolyte fuel cell by using redox mediator for the electrode reaction. Heteropolyacid solutions were selected as positive electrode mediators, and the additive effects of acids and metal ions on the reduction and reoxidation reactions of heteropolyanions were clarified. In the reductive regeneration reaction of redox mediator at the negative electrode, carbon monoxide-containing hydrogen and oxalic acid were employed as fuels, and a carbon-supported rhodium phthalocyanine complex suspended in a solution could be used as a pseudo-homogeneous catalyst. Furthermore, we developed a cell system in which a gas phase between both electrodes prevented the mixing of the anode and the cathode solutions. The operation of this system was demonstrated in combination with the reactions of both electrodes, and the voltage-current relationship in the steady state was obtained.

Free Research Field

無機固体化学

Academic Significance and Societal Importance of the Research Achievements

本研究では、Ptを両極に使用しない燃料電池という画期的なシステム実現に向けた研究成果を得ることができた。また、利用可能な燃料選択肢が広がることは、燃料電池に利用用途の拡大をもたらす。これらは、資源・エネルギー問題の解決に貢献し、将来的な省エネルギー・脱炭素社会へ寄与する内容である。また、ヘテロポリ酸に燃料電池の電極反応を媒介させるという研究例はほとんどなく、このような燃料電池の開発が進展すると、ヘテロポリ酸の新しい科学が拓くことにもつながる。