CO oxidation on Ir(111) surfaces under large non-gaussian noise

Area of Science:

• Surface science
• Chemical kinetics
• Statistical mechanics

Background:

• CO oxidation on Ir(111) surfaces is a key catalytic reaction.
• External noise in feed gas composition can significantly impact reaction dynamics.
• Understanding non-Gaussian noise effects is crucial for accurate modeling of surface reactions.

Purpose of the Study:

• To investigate the impact of large, autocorrelated external noise on CO oxidation on Ir(111).
• To analyze the resulting reaction rate fluctuations and their statistical properties.
• To propose a suitable theoretical model for these phenomena.

Main Methods:

• Experimental studies of CO oxidation on Ir(111) under controlled noise conditions.
• Theoretical analysis of reaction dynamics influenced by non-Gaussian feed gas fluctuations.
• Development and application of a continuous-time discrete-state Markov process model.

Main Results:

• Experimental results demonstrate that fluctuations force the reaction rate to jump between two distinct states.
• The statistics of the reaction rate are directly dependent on the external noise characteristics.
• Neither the noise nor the reaction rate exhibit Gaussian distributions, ruling out simple white or colored noise models.

Conclusions:

• A continuous-time discrete-state Markov process effectively models the observed phenomena.
• The proposed model captures key features of fluctuations under non-Gaussian external noise.
• The model can be adapted for other surface reactions and systems subjected to similar noise conditions.