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Simulation of methane oxidation on Pt.
V P Zhdanov1, P-A Carlsson, B Kasemo
1Competence Centre for Catalysis, Chalmers University of Technology, S-412 96 Göteborg, Sweden.
The Journal of Chemical Physics
|June 30, 2007
Summary
This study models methane (CH4) oxidation on platinum (Pt), revealing how surface oxide formation causes stepwise reaction kinetics. Changes in CH4 and O2 pressure drive transitions between low and high reactivity states.
Area of Science:
- Catalysis
- Chemical Kinetics
- Surface Science
Background:
- Methane (CH4) oxidation on platinum (Pt) is crucial for catalysis.
- Surface-oxide formation plays a significant role in catalytic processes.
- Understanding reaction kinetics under varying conditions is essential.
Purpose of the Study:
- To develop a generic model for CH4 oxidation on Pt.
- To investigate the influence of surface-oxide formation on reaction kinetics.
- To explain experimental observations through kinetic modeling.
Main Methods:
- Development of a generic kinetic model for CH4 oxidation on Pt.
- Application of first-order phase transition theory to surface-oxide formation.
- Utilizing Monte Carlo simulations to analyze reaction kinetics.
Main Results:
- Surface-oxide formation can lead to stepwise features in reaction kinetics.
- A sharp transition occurs between oxide-covered (low reactivity) and oxygen-covered (high reactivity) states.
- Reaction orders for CH4 and O2 vary depending on the surface state.
Conclusions:
- The model successfully explains experimental data on CH4 oxidation on Pt.
- Surface-oxide formation is a key factor controlling the reaction pathway and kinetics.
- The study provides insights into the complex interplay between surface chemistry and catalytic activity.
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