CO酸化反応のPd (n) /TiO2 (n) /TiO2 (n) /TiO2 (n) /TiO2 (n) /TiO2 (n) /TiO2 (n) /TiO2 (n) /TiO2 (n) /TiO2 (n) /TiO2 (n)
William E Kaden1, William A Kunkel, Matt D Kane
1Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112-0850, USA.
Journal of the American Chemical Society
|September 3, 2010
まとめ
TiO (((2) ((110) 上のパラジウムクラスタサイズは,酸素活性化に大きく影響します. Pd(20) は,より小さなクラスターとは異なり,CO酸化機構に影響を与える高い効率を示しています.
科学分野:
- 表面科学とは,地表科学のことである.
- 異質なカタリシスである.
- ナノ素材 ナノ素材
背景:
- 金属酸化物の支柱における酸素活性化の理解は,触媒作用において極めて重要です.
- TiO ((2) ((110) 上のパラジウムクラスターは,サイズに依存する触媒特性を研究するためのモデルシステムです.
- これらの表面における酸素と一酸化炭素 (CO) の相互作用が反応経路を決定する.
研究 の 目的:
- Pd{n}/TiO{2}{110) クラスターにおける酸素の解離結合効率を調査する.
- パラジウムクラスタサイズ (n=4,7,10,20) が酸素活性化とCO酸化に及ぼす影響を決定する.
- 電子の性質を触媒的活動と反応機構と相関させる.
主な方法:
- 温度プログラム反応 (TPR) 質量スペクトロメトリー.
- X線光放出スペクトロスコーピー (XPS).
- 制御されたO (((2) とCOの曝露を,様々な量と温度で測定する.
主要な成果:
- Pd(20)/TiO(2)(110) は,より小さなPd(n) クラスターと比較して,より優れた酸素活性化効率を示しています.
- CO酸化活動は,より小さなクラスターではO2の活性化によって制限されるが,低O2用量ではPd2のCO結合によって制限される.
- 特定のCO結合部位が,CO2の生成に反応する部位として特定された.
結論:
- パラジウム・クラスターの大きさは,TiOの酸素活性化とCO酸化のメカニズムを決定する.
- Pdクラスターの電子特性は,そのサイズに依存する触媒性能の鍵です.
- 反応性結合部位を特定することは,効率的な触媒システムの設計に不可欠です.
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