高度に強化された酸素進化触媒のためのスピネル酸化物における四面体位における選択的原子置換によるバレンスの工学
Yan Liu1, Yiran Ying1, Linfeng Fei1
1Department of Applied Physics , The Hong Kong Polytechnic University , Hung Hom, Kowloon , Hong Kong , China.
Journal of the American Chemical Society
|April 25, 2019
まとめ
ニッケル・コバルト酸化物に鉄を加えると,酸素進化反応 (OER) の性能が著しく向上する. この新しい触媒材料は,超低ポテンシャルを達成し,OERの実用的なアプリケーションの主要な障害を克服します.
科学分野:
- 電気化学
- 材料科学
- キャタリシス
背景:
- 高超電位は,酸素進化反応 (OER) で移行金属酸化物の実用的な使用を制限する.
- 電子構造と吸収エネルギーを最適化することは,効率的なOER触媒にとって極めて重要です.
研究 の 目的:
- ニコスピネル酸化物のOER性能に対する鉄ドーピングの影響を調査する.
- ニコ酸化物におけるFeの位置偏好とその触媒活動への影響を理解する.
主な方法:
- テトラエドールサイトにおけるFeのエネルギー優位性を決定するための理論的計算.
- ニコフェオキシド触媒の合成
- Feドーピング部位と酸化状態を分析するためのX線吸収スペクトロスコーピー (XAS).
主要な成果:
- Feはニコスピネル酸化物における四面体部位を優遇的に占めている.
- このドーピングは,オクタエドール部位にNi3+とCO2+を誘導し,OERの活性を増強します.
- NiCoFe酸化物触媒は10 mA cm−2で201 mV cm−2の超低ポテンシャルと39 mV dec−1のタフェル傾斜を達成した.
結論:
- ニコアスピネル酸化物におけるFeドーピングは,OERの性能を高めるための効果的な戦略です.
- Feによる四面体部位の優先占用は,優れた触媒のための電子構造を最適化します.
- 開発されたNiCoFe酸化物触媒は,Ni-Coベースの最先端の触媒を上回ります.
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