単原子触媒における調整環境の調整により,高効率の酸素減少反応が達成される
Jinqiang Zhang1, Yufei Zhao1, Chen Chen2
1Center for Clean Energy Technology, School of Mathematical and Physical Sciences, Faculty of Science , University of Technology Sydney , Ultimo , New South Wales 2007 , Australia.
Journal of the American Chemical Society
|December 6, 2019
まとめ
効率的な酸素還元反応 (ORR) のための N,S-コード化炭素の単金属原子触媒を開発しました. 鉄中心の触媒 (Fe-SAs/NSC) はコバルトとニッケルに比べて優れた性能と安定性を示し,商業用プラチナ/炭素を上回った.
科学分野:
- 材料科学
- 電気化学
- カタリシス
背景:
- 原子的に分散した金属触媒は,酸素還元反応 (ORR) を通して効率的なエネルギー変換に不可欠です.
- 高活性で安定したORR触媒の開発は,燃料電池技術の進歩に不可欠です.
研究 の 目的:
- ORRのために,多孔なN,S-コーデッド炭素 (NSC) に固定された単一の金属原子を合成し,調査する.
- NSCにおけるFe,Co,Ni単原子触媒 (SAC) の構造性能相関を調査する.
- メタル-リガンドの協調が触媒活動に及ぼす影響を理解する.
主な方法:
- テンプレートアシスト合成のN,S-コーデッド炭素マトリックス.
- 単一のFe,Co,Ni原子をNSCマトリックスに固定する.
- 先進的な分析技術を用いた構造的特徴付け
- ORRの活性と安定性の電気化学的評価
- 反応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:
- 異なる調整環境が観察された:Fe-SAs/NSCはFeN4S2サイトを特徴とし,Co-SAs/NSCとNi-SAs/NSCはMN3S1サイトを形成するM-Sボンドを示した.
- FeN4S2は,好ましい電子特性と低エネルギーバリアにより,より高い活性性を予測した.
- Fe-SAs/NSCは商用Pt/Cを上回る優れたORR性能を示し,優れたメタノール耐性と長期安定性 (5000サイクル) を示した.
結論:
- 単一の金属原子の調整構造はORRの触媒活動に大きく影響する.
- Fe-SAs/NSCは高効率で安定したORR触媒であり,プラチナベースの触媒の有望な代替品です.
- この研究は,エネルギーアプリケーションのための調整可能な性質を持つ単原子触媒の合理的な設計のための重要な洞察を提供します.
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