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Updated: Dec 21, 2025
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Multiscale Sampling of a Heterogeneous Water/Metal Catalyst Interface using Density Functional Theory and Force-Field Molecular Dynamics
Published on: April 12, 2019
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Competing ternary surface reaction CO + O2 + H2 on Ir(111)
Kevin Rohe1, Jaime Cisternas2, Stefan Wehner1
1Surface Science Group, Institute for Integrated Natural Sciences, University of Koblenz-Landau, Universitätsstraße 1, 56070 Koblenz, Germany.
Proceedings. Mathematical, Physical, and Engineering Sciences
|May 14, 2020
Summary
This study models the CO oxidation reaction with hydrogen addition, revealing complex surface dynamics. Bifurcation theory shows how up to three stable states emerge, impacting experimental outcomes.
Area of Science:
- Surface Science
- Chemical Kinetics
- Physical Chemistry
Background:
- CO oxidation on platinum-group metals is a well-studied surface reaction.
- Competing reactions and the influence of additional gases like hydrogen are often overlooked.
- Hydrogen is crucial in technical applications and ubiquitous in vacuum environments.
Purpose of the Study:
- To present and discuss a model for the competing surface reactions of CO, O2, and H2.
- To analyze the complex dynamics arising from hydrogen addition to CO oxidation.
- To explore the theoretical framework for understanding multi-stable states in surface reactions.
Main Methods:
- Application of bifurcation theory to model the extended reaction system.
- Numerical exploration of the system's steady states and their stability.
- Approximative first-principle approach to diffusion modeling.
Main Results:
- The extended system exhibits a swallowtail catastrophe set with a tristable regime.
- Numerical simulations demonstrate the possibility of reaching all three stable states.
- Diffusion modeling illustrates pattern formation arising from the balance of multiple stable states.
Conclusions:
- The presence of hydrogen significantly complicates CO oxidation dynamics on platinum-group metals.
- Bifurcation theory provides a powerful framework for understanding complex surface reaction phenomena.
- The study highlights potential experimental challenges and the formation of heterogeneous patterns due to multi-stability.
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