酸素還元反応の活性サイトとしての炭素欠陥における原子結合種の調整
Longzhou Zhang1, Julia Melisande Theresa Agatha Fischer2, Yi Jia1
1School of Environment and Science and Queensland Micro- and Nanotechnology Centre , Griffith University , Nathan Campus, Nathan , Queensland 4111 , Australia.
Journal of the American Chemical Society
|August 8, 2018
まとめ
窒素-炭素 (A-CoPt-NC) 上のプラチナ-コバルトの原子分散は,より優れた酸素還元反応 (ORR) の活性と耐久性を表しています. この画期的な発明は,広く利用されているORR用の伝統的なプラチナ触媒に費用対効果の高い代替手段を提供します.
科学分野:
- 電気化学
- 材料科学
- キャタリシス
背景:
- プラチナ (Pt) は酸素還元反応 (ORR) の主要な触媒ですが,コストと希少性に制限されています.
- 大規模なアプリケーションの限界を克服するために,Ptの使用を減らすことが重要です.
- 原子的に分散した金属触媒は高い活性と原子効率を提供し,このニーズを満たす可能性があります.
研究 の 目的:
- 効率的なORRのための新しい低Pt触媒を開発し,特徴づけること.
- 窒素-炭素基上に原子Pt-Coの触媒性能とメカニズムを調査する.
- 従来のプラチナ製の触媒に 適した代替手段を提示する
主な方法:
- 局所分布の原子Pt-Co窒素炭素基触媒 (A-CoPt-NC) の合成
- 質量活性比較を含むORR活性と耐久性を評価するための電気化学試験.
- 触媒メカニズムを解明するための密度関数理論 (DFT) の計算.
主要な成果:
- A-CoPt-NC触媒は,商用Pt/Cと比較して,かなり高い質量活性 (267倍) と堅固な耐久性を示した.
- A-CoPt-NCは,原子Pt触媒の2e-経路とは異なるORRにおける4e-経路を選択的に好む.
- DFTの計算では,原子Pt-Coと欠陥C/Nのグラフェン表面 (N8V4の空白) の間の相乗効果が明らかになり,高い活性をもたらした.
結論:
- 窒素-炭素基の原子分散型Pt-Co触媒は,ORRにとって非常に活発で耐久性があります.
- この性能の向上は,N8V4の空白における原子Pt-Coの協調から生じるシネージ効果とユニークな電子特性に起因する.
- この触媒の設計は,ORRアプリケーションにおけるプラチナ含有量を減らすための有望な戦略を示しています.
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