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Kinetics of chemical reactions on solid surfaces: deviations from conventional theory
1Department of Chemistry, University of California, Riverside, California 92521, USA. francisco.zaera@ucr.edu
Accounts of Chemical Research
|February 20, 2002
Summary
Surface reactions deviate from standard theories because neighboring molecules alter reaction energy. Advanced models must account for these local effects and changing adsorption patterns for accurate surface kinetics.
Area of Science:
- Surface Science
- Chemical Kinetics
- Physical Chemistry
Background:
- Conventional kinetic theories often fail to explain observed reaction rates on solid surfaces.
- Existing macroscopic models do not fully capture the complex interactions between adsorbed species.
Purpose of the Study:
- To investigate deviations in isothermal kinetic measurements of elementary surface reactions.
- To identify factors influencing surface reaction energetics beyond standard kinetic models.
Main Methods:
- Performed isothermal kinetic measurements on species adsorbed on solid surfaces.
- Analyzed deviations from conventional kinetic theories and macroscopic models.
Main Results:
- Neighboring adsorbates significantly modify surface reaction energetics, a factor not explained by macroscopic models.
- Free energy barriers require coverage-dependent terms, but local effects like surface islanding remain unaccounted for.
- Changes in surface concentration alter adsorption geometries and adsorbate-surface bonding.
Conclusions:
- Standard kinetic theories are insufficient for describing surface reactions accurately.
- Future theoretical approaches, including Monte Carlo simulations, must incorporate local effects, surface islanding, and coverage-dependent bonding for improved surface kinetics modeling.