Ring Polymer Molecular Dynamics Approach to Quantum Dissociative Chemisorption Rates
Liang Zhang1, Junxiang Zuo1, Yury V Suleimanov2
1Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States.
The Journal of Physical Chemistry Letters
|August 2, 2023
Summary
A new ring polymer molecular dynamics (RPMD) method accurately calculates dissociative chemisorption rates, including quantum effects like tunneling, for molecules such as H2 on metal surfaces.
Area of Science:
- Surface science
- Chemical kinetics
- Computational chemistry
Background:
- Dissociative chemisorption is crucial for many surface reactions.
- Accurately modeling quantum effects like zero-point energy and tunneling is challenging.
- Classical methods often fail to capture low-temperature behavior.
Purpose of the Study:
- To develop and validate a new computational method for calculating dissociative chemisorption rates.
- To incorporate quantum mechanical effects into molecular dynamics simulations.
- To investigate the role of quantum effects in H2 chemisorption on metal surfaces.
Main Methods:
- Proposed a ring polymer molecular dynamics (RPMD) method.
- Applied RPMD to H2 dissociative chemisorption on Ag(111) and Pt(111) surfaces.
- Utilized classical trajectories within the RPMD framework to simulate quantum phenomena.
Main Results:
- RPMD accurately predicts H2 chemisorption on Pt(111) within experimental uncertainty.
- Observed significant deviations from Arrhenius behavior at low temperatures for H2 on Ag(111), attributed to tunneling.
- Demonstrated the importance of quantum effects, including tunneling and zero-point energy, in dissociative chemisorption.
Conclusions:
- The proposed RPMD method is a reliable tool for studying dissociative chemisorption.
- Quantum effects play a critical role in the kinetics of dissociative chemisorption, especially at low temperatures.
- RPMD provides a computationally tractable approach to include quantum effects in surface reaction dynamics.
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