塩基媒体の酸素還元反応はFe-N-C電解剤から鉄の浸出を引き起こします
Yu-Ping Ku1,2, Konrad Ehelebe1,2, Andreas Hutzler1
1Helmholtz-Institute Erlangen-Nürnberg for Renewable Energy (IEK-11), Forschungszentrum Jülich GmbH, Cauerstraße 1, 91058 Erlangen, Germany.
Journal of the American Chemical Society
|May 24, 2022
まとめ
鉄-窒素-炭素 (Fe-N-C) 電気触媒は燃料電池 (FC) に期待を寄せている. この研究は,酸素還元反応 (ORR) の活動と鉄溶解の間の直接的な関連性を明らかにし,新しい安定性メトリックを導入した.
科学分野:
- 電気化学
- 材料科学
- カタリシス
背景:
- 鉄-窒素-炭素 (Fe-N-C) 電気触媒は,燃料電池 (FC) のアルカリ媒体でプラチナのような活性を示します.
- 高い耐久性と耐久性を示すことは,FCの広範な適用に不可欠です.
- 操作条件下での分解経路の理解が限られているため,安定したFe-N-C触媒の開発が困難である.
研究 の 目的:
- 燃料電池に関連する条件下でFe-N-C電解体から鉄 (Fe) の溶解を調査する.
- 電気化学的活動とFeの分解の量的な関係を確立する.
- 電気触媒の安定性を評価するための新しいメトリックを導入する.
主な方法:
- 誘導結合プラズマ質量計 (ICP-MS) と結合したガス拡散電極半セルを使用した.
- 毛細な触媒層 (CLs) および高電流密度 (-125 mA·cm-2) を含むFC環境を模倣した条件下で動作する.
- Fe溶解に対する効果を研究するために,酸素還元反応 (ORR) の速度を変化させた.
主要な成果:
- 通過したファラダイク電荷と溶解したFeの量との間の線形相関が観察された.
- この相関は,ORRとFe溶解の間のメカニズム的リンクを示唆し,Feリドックス移行における一般的な中間物質を介して可能性があります.
- この線形関係に基づいて,新しい安定性メトリックであるS番号が開発されました.
結論:
- Fe-N-C電触媒におけるFe溶解は,ORRで通過する電荷と正比である.
- S番号は,電気触媒の迅速な安定性スクリーニングのためのシンプルで強力なツールを提供します.
- この研究は,触媒層におけるFe-N-C分解のメカニズム的な理解を高め,より耐久性の高い触媒の設計を容易にする.
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