ナノポーラス電気触媒における酸素還元による水素進化抑制
Ellen E Benn1, Bernard Gaskey1, Jonah D Erlebacher1
1Department of Materials Science and Engineering, Johns Hopkins University , Baltimore, Maryland 21218, United States.
Journal of the American Chemical Society
|February 18, 2017
まとめ
研究者は,ナノ孔性のニッケル・プラチナ電極への陽子と反応物質の輸送を制御することによって,電還元時に水素進化反応 (HER) を抑制しました. この戦略は酸素還元反応 (ORR) の選択性と活性性を高めます.
科学分野:
- 電気化学
- 材料科学
- 化学工学
背景:
- 水素進化反応 (HER) は,しばしば望ましい電還元反応と競合する.
- 過剰な潜在力は競争を悪化させ効率を低下させます
- 反応物質の輸送を制御することは,選択的電気触媒にとって極めて重要です.
研究 の 目的:
- 陽子と反応物質の電気触媒への輸送運動を調査する.
- 輸送と触媒性能の関係を理解する.
- HERを抑制し,酸素還元反応 (ORR) の選択性を高める戦略を開発する.
主な方法:
- 酸性電解質での陽子拡散制限条件下でORRを研究した.
- 非合金化ナノポラスニッケル・プラチナ (np-NiPt) 電極を使用しています.
- 交差点のpH効果を検出するために,バッファリングとバッファリングされていない溶液を比較した.
主要な成果:
- 超高電位 (RHE対-400mV) でさえも,HERを完全に抑制した.
- 緩衝と緩衝のない溶液がORRメカニズムを変更することを実証した.
- インターフェイス pH の一時的な変化にリンクされた反応選択性.
結論:
- 過剰ポテンシャルで反応物質の輸送を制御することは,一般化可能な戦略を提供します.
- このアプローチは,電還元反応における活性と選択性を著しく増加させることができます.
- 表面 pH は ORR の選択性を決定する上で重要な役割を果たします.
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