Kinetic analysis of interaction between N atoms and O-covered Ru(0001)

Area of Science:

• Surface science
• Chemical kinetics
• Atomic and molecular physics

Background:

• Eley-Rideal (ER) reactions involve gas-phase atoms reacting with surface-adsorbed species.
• Previous experiments observed ER reactions of heavier atoms, yielding varied reaction cross-section data.
• A proposed "shielding" effect by nitrogen adatoms was suggested to explain high cross-section measurements.

Purpose of the Study:

• To investigate the reaction kinetics of Eley-Rideal reactions involving nitrogen and oxygen.
• To model the observed reaction dynamics using a rate equation approach.
• To evaluate the proposed surface "shielding" mechanism.

Main Methods:

• Application of a rate equation model incorporating two ER pathways and an adsorption process.
• Analysis of experimental data from molecular beam experiments, focusing on full-beam exposure.
• Derivation of individual reaction cross-section values.

Main Results:

• The model successfully describes the measured nitrogen (N2) product response.
• The model is insufficient to fully capture the nitric oxide (NO) product response.
• Individual reaction cross sections for N-Oad and N-Nad ER processes were derived.

Conclusions:

• The rate equation model provides a partial explanation for the observed Eley-Rideal reaction kinetics.
• Discrepancies in the nitric oxide response suggest complexities not fully captured by the current model.
• Further refinement is needed to fully understand the surface effects influencing these reactions.