選択されたゴールドクラスターのCOとO2の共同吸収:効率的な室温CO2生成の証拠
William T Wallace1, Robert L Whetten
1School of Chemistry and Biochemistry and the School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA.
Journal of the American Chemical Society
|June 20, 2002
まとめ
アニオン黄金のクラスターは,一酸化炭素と酸素の共同吸収を示し,反応性を高めます. 金-6アニオン (Au(6) ((-)) は,商用触媒よりも100倍速く一酸化炭素を酸化する.
科学分野:
- 物理化学 物理化学
- 表面科学とは,地表科学である.
- ナノ素材 ナノ素材
背景:
- サポートされた黄金クラスターの反応性は,サイズとサポートに依存することが知られている.
- ガス相アニオン黄金のクラスターは,基本的な反応性を研究するための簡素化されたモデルシステムを提供します.
研究 の 目的:
- アニオニックゴールドクラスター (Au(N) ((-)) において,一酸化炭素 (CO) と酸素 (O2) の共吸収を調査する.
- クラスターサイズと反応物質のプレアドソルプションが,アドソルプションの行動と反応性に与える影響を決定する.
主な方法:
- アニオン黄金のクラスターを含むガス相実験.
- クラスターのCOとO2への暴露は,個別に,また同時に.
- 反応産物と運動を分析するための質量スペクトロメトリー.
主要な成果:
- 酸素吸収はバイナリ (0,1) のパターンで,均等サイズのクラスターは反応性を示し,奇数サイズのクラスターは反応性を示さない.
- 炭素一酸化物の吸収は大きさに依存し,N=4から19までのクラスターでは発生するが,ダイマーやトリマーでは発生しない.
- 同吸附は協力的効果につながり,ある反応物が他の反応物の吸附を強める.
- ゴールド-6アニオン (Au(6) ((-)) は重要な触媒活性を示し,ゴールド触媒の報告よりも100倍速くCOを酸化する.
結論:
- アニオン黄金のクラスターは,COとO2の吸収に対するサイズ依存の反応性を示す.
- ゴールドクラスターにおけるCOとO2の共吸収は協力的であり,競争的ではない.
- ガス相のアニオンであるAu(6)(-) は,COの酸化に対して例外的な触媒効率を示している.
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