Pt(111) 単一結晶表面上の2-ブーテンにおけるトランス・トゥ・シス・イソメリゼーションの選択性の起源
Françoise Delbecq1, Francisco Zaera
1Department of Chemistry, University of California, Riverside, California 92521, USA.
Journal of the American Chemical Society
|October 22, 2008
まとめ
密度関数理論 (DFT) の計算は,トランス-2ブーテンがプラチナ表面でシス-2-ブーテンに変換する理由を説明します. 低分子再構成と,シス同位体吸附中の表面再構築が,この選択性を駆動する.
科学分野:
- 表面科学とは,地表科学である.
- カタリシス カタリシス カタリシス
- コンピューティング・ケミストリー
背景:
- 金属表面でのアルケンの変換は,触媒作用において極めて重要です.
- 以前の研究では,Pt上でのトランス-2-ブーテンから,より不安定なシス-2-ブーテン同位体を形成する予期せぬ好みが観察されました.
研究 の 目的:
- トランス-2-ブーテンからシス-2-ブーテンの選択的形成を制御する根本的なメカニズムと要因を明らかにする.
- 理論的な計算を用いて観察された反応選択性を説明する.
主な方法:
- 密度関数理論 (DFT) の計算が採用されました.
- 分析は,Pt ((111)) の吸着エネルギーと表面プロセスに焦点を当てました.
主要な成果:
- DFT計算は,水素で覆われたPtのトランス同位体と比較して,cis同位体の吸附には分子再配置が少なく必要であることを明らかにしています.
- 表面再構築は,cis同位体の吸収にもあまり重要ではない.
- これらの要因は,シス-2-ブーテンの形成に対する観察された好みに寄与しています.
結論:
- 水素の覆面と表面の原子再構成は,このシステムにおける吸収エネルギーと反応選択性の重要な決定因子である.
- この発見は,より不安定なシス同位体の好ましい合成の理論的説明を提供します.
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