Understanding Electron Transfer Reactions Using Constrained Density Functional Theory: Complications Due to Surface...

Area of Science:

• Electrochemistry
• Computational Chemistry
• Materials Science

Background:

• Electrochemical reaction kinetics are vital for flow battery performance.
• Efficient electron transfer between electrolyte molecules and electrodes is critical.

Purpose of the Study:

• Develop a systematic, atomic-level computational protocol to study electron transfer.
• Enable realistic predictions of electron transfer kinetics for energy storage applications.

Main Methods:

• Constrained density functional theory (CDFT) to localize electrons.
• Ab initio molecular dynamics (AIMD) to simulate atomic movement.
• Marcus theory combined with CDFT-AIMD to compute electron transfer parameters.

Main Results:

• Modeled electron transfer between graphene electrodes and various organic electrolyte molecules.
• Demonstrated a protocol for calculating electron transfer rates at the atomic level.
• Identified challenges in evaluating outer-sphere electron transfer due to strong electrode-molecule interactions.

Conclusions:

• The developed CDFT-AIMD protocol provides a pathway for accurate prediction of electron transfer kinetics.
• This approach is crucial for designing and optimizing advanced energy storage systems.
• Further refinement is needed to fully address outer-sphere electron transfer mechanisms.