Electrical Double Layer in Electrocatalysis: Definitions, Characterization, and Influencing Factors

Area of Science:

• Electrochemistry
• Materials Science
• Physical Chemistry

Background:

• The electrical double layer (EDL) at the electrode-electrolyte interface critically influences electrochemical reaction kinetics and device performance.
• Classical EDL models are challenged by solvation effects, ion adsorption, and product evolution, necessitating a nonclassical approach.
• Emerging experimental techniques are revealing previously unknown properties of the EDL.

Purpose of the Study:

• To redefine the features and characteristics of the electrical double layer (EDL).
• To provide a comprehensive framework for understanding EDL structure and behavior.
• To review factors influencing EDL in various electrochemical reactions.

Main Methods:

• Literature review of classical and nonclassical EDL theories.
• Summary of diverse experimental and theoretical methods for EDL characterization.
• Analysis of factors affecting EDL in electrochemical systems.

Main Results:

• A redefined understanding of EDL features, incorporating solvation, adsorption, and evolution.
• A structured overview of EDL quantification techniques.
• Identification of key factors influencing EDL across different electrochemical reactions.

Conclusions:

• Advances in understanding EDL properties will reshape electrochemical device design, catalyst synthesis, and electrolyte engineering.
• Clarifying EDL characteristics and characterization is vital for advancing electrochemistry and electrochemical catalysis.
• This review provides a foundation for future innovations in the field.