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Oscillatory kinetics and spatio-temporal self-organization in reactions at solid surfaces.
Science (New York, N.Y.)
|December 20, 1991
Summary
Nonlinear dynamics in surface chemical reactions, like CO oxidation on platinum, can lead to oscillations and chaos. These reactions form complex spatio-temporal patterns, including waves and chemical turbulence.
Area of Science:
- Surface chemistry
- Chemical kinetics
- Nonlinear dynamics
Background:
- Chemical reactions far from equilibrium on solid surfaces can display complex dynamic behaviors.
- The catalytic oxidation of carbon monoxide on platinum(111) single-crystal surfaces serves as a model system for studying these phenomena.
Purpose of the Study:
- To investigate the nonlinear dynamic phenomena observed in surface chemical reactions.
- To understand the formation of spatio-temporal patterns during the catalytic oxidation of carbon monoxide.
Main Methods:
- Studying the catalytic oxidation of carbon monoxide on a platinum(110) single-crystal surface.
- Varying external parameters such as temperature and partial pressures of reactants.
- Observing temporal variations in reaction rate and spatial concentration distributions of adsorbed species.
Main Results:
- Observed oscillatory and chaotic temporal variations in the reaction rate.
- Identified spatio-temporal patterns including propagating and standing waves, and rotating spirals.
- Documented irregular and rapidly changing structures termed "chemical turbulence".
Conclusions:
- Surface chemical reactions far from equilibrium exhibit phenomena characteristic of nonlinear dynamics.
- External parameters significantly influence the reaction dynamics, leading to complex temporal and spatial behaviors.
- The catalytic oxidation of CO on Pt(110) demonstrates a rich variety of nonlinear phenomena, including chemical turbulence.
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