Carbonate formation and decomposition on atomic oxygen precovered Au(111)
Rotimi A Ojifinni1, Jinlong Gong, Nathan S Froemming
1University of Texas at Austin, Departments of Chemical Engineering and Chemistry, Center for Nano- and Molecular Science and Technology, and Texas Materials Institute, 1 University Station C0400, Austin, Texas 78712-0231
Journal of the American Chemical Society
|August 6, 2008
Summary
This study reveals carbonate formation and reaction on gold surfaces using oxygen and labeled carbon dioxide. These findings advance our understanding of surface chemistry and catalysis.
Area of Science:
- Surface Science
- Chemical Kinetics
- Computational Chemistry
Background:
- Gold surfaces are crucial in catalysis.
- Understanding oxygen and CO2 interactions is key for catalyst design.
- Atomic oxygen plays a significant role in surface reactions.
Purpose of the Study:
- To investigate carbonate formation and reaction on atomic oxygen precovered Au(111).
- To elucidate the mechanism of oxygen isotope exchange during CO2 interaction with oxygenated gold surfaces.
- To determine the reaction kinetics and energetics of surface carbonate formation and decomposition.
Main Methods:
- Experimental studies using temperature-programmed desorption (TPD) with isotopically labeled CO2 (C18O2).
- Density functional theory (DFT) calculations to support experimental observations.
- Varying surface temperatures (77-400 K) and initial oxygen coverages (0.18-2.1 ML).
Main Results:
- Observed oxygen mixing (formation of 16O18O) indicating carbonate formation and decomposition.
- Surface carbonate formation and decomposition occur between 77-400 K.
- Estimated reaction probability of ~10(-4) and activation energy of -0.15 ± 0.08 eV.
Conclusions:
- Experimental and computational results confirm carbonate formation and reaction pathways on Au(111).
- Oxygen isotope exchange provides direct evidence for surface carbonate intermediates.
- The study quantifies reaction kinetics, offering insights into catalytic processes on gold surfaces.
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