An Interfacial View of Cation Effects on Electrocatalysis Systems

Area of Science:

• Electrochemistry
• Materials Science
• Surface Chemistry

Background:

• Alkali metal cations in electrolytes significantly impact electrocatalytic reaction kinetics and efficiency.
• Understanding cation effects at the molecular level is crucial for optimizing electrocatalytic processes.

Purpose of the Study:

• To review recent advances in understanding cation effects on electrocatalytic reactions.
• To summarize the influence of alkali metal cations on hydrogen evolution (HER), oxygen evolution (OER), and CO2 electroreduction (CO2 RR).

Main Methods:

• Literature review of molecular-level understanding of cation effects.
• Analysis of cation influence on interfacial electric fields, water structure, active site blocking, intermediate stabilization, and interfacial pH.
• Discussion of experimental and theoretical findings.

Main Results:

• Cation-induced interfacial phenomena, including electric fields and water structuring, affect electrocatalytic performance (activity, selectivity, stability).
• General agreement exists on the relationship between alkali cation size and reaction activity for HER, OER, and CO2 RR.
• Mechanisms of cation influence on electrocatalytic performance are still under debate.

Conclusions:

• Alkali metal cations are pivotal in tailoring electrocatalysis, influencing interfacial properties and reaction outcomes.
• While cation size-activity trends are recognized, the precise mechanisms require further investigation.
• Targeting cation-electrolyte interactions offers a pathway for designing advanced electrocatalytic systems.