Pt3Niナノフレーム電触媒の原子構造
Nigel Becknell1, Yijin Kang2, Chen Chen1
1Department of Chemistry, University of California , Berkeley, California 94720, United States.
Journal of the American Chemical Society
|December 15, 2015
まとめ
現場で触媒の構造を研究することは,性能の鍵です. Pt3Niナノフレームでは,高酸素還元反応 (ORR) の活動は,保護性プラチナ皮の表面を形成することに依存しています.
科学分野:
- 材料科学
- 電気化学
- カタリシス
背景:
- 触媒の性能は 原子構造と密接に関連しています
- 触媒は反応条件下でしばしば変化し,その場での研究が必要となる.
- Pt-Ni触媒は酸素還元反応 (ORR) の有望であるが,その表面的行動は詳細な調査を必要とする.
研究 の 目的:
- Pt3Niナノフレーム電触媒の in situ原子構造を調査する.
- 表面構造と酸素還元反応 (ORR) の性能を相関させる.
- Pt皮膚形成のメカニズムとそのORR活動への影響を理解する.
主な方法:
- 反応条件下で触媒の構造を検知するX線吸収スペクトロスコーピー (XAS).
- 表面結合特性を評価するために,電気化学的水素低電位堆積と一酸化炭素の電気酸化.
- 触媒状態を比較するためのex situとin situのXAS分析
主要な成果:
- ナノフレームの表面は,構造的な違いと相関する,アドソルベートへの結合強度が異なる.
- Pt分離とNi溶解が不完全であるため,より強いアドソルバート結合は,より粗なPt表面と関連しています.
- 高いORR活動は,有意なPt分離と相関し,有益なPt皮膚層を形成する.
結論:
- Pt3Niの空洞ナノフレームの高いORR活動は,Pt皮の表面構造の形成に決定的に依存しています.
- ダイナミックな触媒の振る舞いを理解するには,in situの特徴づけが不可欠です.
- ORR電触媒の最適化には,Pt分離とNi溶解を制御することが重要です.
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