Electrochemistry-Enhanced Dynamic Path Sampling for Reaction Rate Calculations Considering Nuclear Quantum Effects.

Area of Science:

• Physical Chemistry
• Computational Chemistry
• Electrocatalysis

Background:

• Proton-coupled electron transfers (PCETs) are fundamental to electrocatalysis.
• Accurate calculation of PCET rates, especially with nuclear quantum effects (NQEs) under constant potential, is challenging.
• Statistical sampling methods for reaction rates are often hindered by the rare-event problem.

Purpose of the Study:

• To develop a novel computational approach for enhanced sampling of reaction paths in electrochemistry.
• To enable realistic simulations of PCET processes under constant potentials without predefined reaction coordinates.
• To investigate the impact of NQEs on the rates of electrochemical reactions.

Main Methods:

• Developed an electrochemistry-driven quantum dynamics approach.
• Implemented enhanced sampling techniques for reaction path exploration.
• Applied the method to model the Volmer step of the hydrogen evolution reaction.

Main Results:

• The new method allows for realistic enhanced path sampling under constant potentials.
• Demonstrated the significant impact of NQEs on computed rate constants.
• Observed that NQEs can alter the rate constant by over an order of magnitude.

Conclusions:

• Nuclear quantum effects play an essential role in electrocatalytic reaction rates.
• The developed computational method provides a powerful tool for studying complex electrochemical processes.
• Accurate modeling of NQEs is crucial for understanding and designing efficient electrocatalysts.