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Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-(phosphinetriyl)tripiperidine]}palladium Under Mild Reaction Conditions
Published on: March 21, 2014
Reaction-path switching induced by spatial-distribution change of reactants: CO oxidation on Pt(111)
1Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
The Journal of Chemical Physics
|September 9, 2004
Summary
We investigated carbon monoxide (CO) oxidation on platinum surfaces. CO coadsorption dynamically altered oxygen distribution, switching between two sequential reaction pathways involving isolated and island-boundary oxygen atoms.
Area of Science:
- Surface science
- Chemical kinetics
- Materials science
Background:
- Understanding catalytic oxidation mechanisms is crucial for industrial applications.
- Platinum surfaces are key catalysts in many chemical reactions, including CO oxidation.
- The role of oxygen adatom distribution in surface reactions requires further elucidation.
Purpose of the Study:
- To elucidate the reaction mechanism of CO oxidation on O-covered Pt(111) surfaces.
- To investigate the influence of CO coadsorption on oxygen adatom distribution.
- To identify distinct reaction pathways and their governing factors.
Main Methods:
- Time-resolved near edge X-ray absorption fine structure (TR-NEXAFS) spectroscopy was employed for in situ monitoring.
- Kinetic measurements were combined with Monte Carlo simulations.
- Analysis focused on the spatial distribution of oxygen atoms on the Pt(111) surface.
Main Results:
- Two distinct, sequential reaction processes for CO oxidation were identified.
- Isolated oxygen atoms and oxygen atoms at island peripheries were found to participate in separate processes.
- CO coadsorption was shown to dynamically alter oxygen adatom distribution, switching reaction paths.
Conclusions:
- The spatial arrangement of oxygen adatoms significantly influences CO oxidation pathways on Pt(111).
- CO coadsorption acts as a dynamic control agent for the reaction mechanism.
- This study provides insights into the complex interplay between reactant coadsorption and surface reaction dynamics.
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