電気触媒による水の酸化に活性な表面電子孔豊かな種

Juan-Jesús Velasco-Vélez^1,2, Emilia A Carbonio^2,3, Cheng-Hao Chuang⁴

¹Department of Heterogeneous Reactions, Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr 45470, Germany.

Journal of the American Chemical Society

|August 6, 2021

まとめ

イリジウム酸化物の触媒は,水を活性化する表面のIr ((V) 種を介して,酸性条件下で水の酸化を促進します. 大量イリジウム種は直接参加せず,より薄い電極は触媒の利用を改善する.

科学分野:

電気化学
材料科学
表面科学

背景:

イリジウムとルテニウム酸化物/水酸化物は,硬い酸性環境における酸素進化反応 (OER) の主要候補である.
鉄酸化物の低過剰電位と高耐腐化は,要求の高い用途に適しています.

研究の目的:

電気触媒による水の酸化過程における活性イリジウム中心の電子構造を解明する.
高性能のIrベースの触媒における表面対散量の役割を理解する.

主な方法:

表面と大量に敏感なX線スペクトロスコピーを利用しました.
特別に設計された電極ナノファブリケーションを使用しています.
密度関数理論 (DFT) の計算を行いました.

主要な成果:

表面上の空のIr 5d状態の形成を特定し,Ir ((V) 種に関連して,水の活性化を推進しました.
表面のμ1-Oとμ1-OHの種は,散発 μ3-Oではなく,水の酸化に重要なものであることが観察されました.
OER中にμ1-OO (ペロキソ) 種の高いカバーを排除した.

結論:

酸素進化反応は表面制御され,単一のイリジウム原子に結合した電子欠乏酸素種によって媒介される.
より薄い電極は,活性種の潜在的降水にもかかわらず,表面対量比を増やすことで材料の使用を向上させます.

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