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Updated: Jun 14, 2026
12:55
Millifluidics for Chemical Synthesis and Time-resolved Mechanistic Studies
Published on: November 27, 2013
Cation-Induced Interphasial Viscosity Variations on Gold Electrocatalysts in Nanoconfined Aqueous Electrolytes
Martin Munz1,2, Shane Carlson3, Leon Jacobse2
1Helmholtz Young Investigator Group Nanoscale Operando CO2 Photo-Electrocatalysis, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin, Germany.
Journal of the American Chemical Society
|June 12, 2026
Summary
Alkali metal cations like potassium (K+) can lubricate interfaces, reducing viscosity in confined electrocatalysis. This study reveals how these ions alter interfacial water structure, impacting molecular mobility.
Area of Science:
- Surface Science
- Physical Chemistry
- Electrocatalysis
Background:
- Interfacial hydration layers are crucial for electrocatalysis and energy conversion.
- Viscosity variations within interfacial zones (interphases) are largely unexplored, especially under nanoconfinement.
Purpose of the Study:
- To investigate the influence of alkali metal cations on the hydrogen-bond network of gold-electrolyte interfaces under nanoconfinement.
- To reveal how interfacial viscosity and density profiles are affected by cation type and concentration.
Main Methods:
- Localized friction force analysis.
- Molecular dynamics simulations.
- Analysis of density and viscosity profiles.
Main Results:
- Potassium cations (K+) exhibit a lubricating effect, decreasing friction with increasing concentration.
- Chaotropic K+ and cesium cations (Cs+) weaken the hydrogen-bond network in chloride electrolytes.
- The interphasial layer shows reduced density and viscosity, followed by a zone of increased viscosity above bulk levels.
Conclusions:
- Alkali metal cations significantly alter interfacial water structure and viscosity.
- Understanding these molecular-level changes is key for optimizing catalysis and electrochemical sensing.
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