Related Experiment Video
Updated: Jun 15, 2025
07:55
Ion-Exchange Membranes for the Fabrication of Reverse Electrodialysis Device
Published on: July 20, 2021
10.5K
Stabilizing Pure Water-Fed Anion Exchange Membrane Water Electrolyzers through Membrane-Electrode Interface
Sinwoo Kang1,2,3, Yeongin Kim1,2,3, Vincent Wilke4
1School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea.
ACS Applied Materials & Interfaces
|August 27, 2024
Summary
Anion exchange ionomer coatings enhance nickel-iron (oxy)hydroxide (NiFeOH) electrocatalyst durability for oxygen evolution reactions. This modification improves stability in pure water-fed electrolyzers by controlling local pH and reducing metal dissolution.
Area of Science:
- Electrochemistry
- Materials Science
- Catalysis
Background:
- Nickel-iron (oxy)hydroxide (NiFeOH) is a promising nonprecious electrocatalyst for the oxygen evolution reaction (OER).
- Anode material instability in pure water-fed electrolyzers limits the durability of NiFeOH catalysts due to nickel and iron dissolution.
Purpose of the Study:
- To enhance the stability and durability of NiFeOH electrocatalysts in pure water-fed electrolyzers.
- To investigate the effect of an anion exchange ionomer coating on the local pH environment and catalyst degradation.
Main Methods:
- Application of an anion exchange ionomer coating to NiFeOH electrocatalysts.
- Stability testing of coated and uncoated catalysts.
- Locally resolved current density measurements.
- In situ Raman spectroscopy in neutral pH electrolyte.
Main Results:
- The ionomer coating created an alkaline local pH environment by extending hydroxide anion diffusion, reducing Ni dissolution.
- Coated NiFeOH catalysts exhibited a 6-fold increase in stability during testing, with significantly lower degradation rates.
- In situ Raman spectroscopy confirmed inhibited Ni oxidation and dissolution with the ionomer coating.
Conclusions:
- Anion exchange ionomer coatings effectively mitigate Ni dissolution and improve the durability of NiFeOH electrocatalysts in pure water-fed electrolyzers.
- This strategy offers a pathway to enhance the long-term performance of nonprecious OER catalysts in demanding electrochemical applications.
Keywords:
in situ Raman spectroscopynickel−iron (oxy)hydroxideoxygen evolution reactionpure water-fed anion exchange membrane water electrolysissegmented cellstabilityMore Related Videos
Related Concept Videos
01:17Ion Exchange
565
Ion exchange chromatography separates charged molecules from a solution by reversibly exchanging them with mobile, or 'active', ions associated with the oppositely charged stationary phase. This method can be used to separate ions, soften and deionize water, and purify solutions. The polymers comprising the ion-exchange column are high-molecular-weight and chemically stable polymers, crosslinked to be porous and essentially insoluble. They are also functionalized with either acidic or...
565
01:15Potentiometry: Membrane Electrodes
499
Membrane electrodes, also known as p-ion electrodes, use membranes that selectively interact with free analyte ions, generating a potential difference across the membrane. The resulting membrane potential, known as the asymmetry potential, is not zero even when analyte concentrations on both sides of the membrane are equal. The membrane's response is typically not selective to a single analyte but proportional to the concentration of all ions in the sample solution capable of interacting at...
499
01:09Ion-Exchange Chromatography
400
Ion-exchange chromatography, or IEC, is a technique for separating ions based on their affinity for the stationary phase. The stationary phase is a cross-linked polymer resin with covalently attached ionic functional groups. The functional groups can be either positively charged (cation exchangers) or negatively charged (anion exchangers). A cation exchanger consists of a polymeric anion and active cations, while an anion exchanger is a polymeric cation with active anions. The choice of...
400
01:15Dialysis
616
Dialysis is a diffusion-based purification process that separates analyte molecules from a complex matrix. This is accomplished by allowing molecules in the solution to pass through a semipermeable membrane into a liquid on the other side. The membrane is usually made of cellulose acetate or cellulose nitrate, and the second liquid must be miscible with the solution. Ions (e.g., chloride or sodium) or organic molecules (e.g., glucose) can pass through the membrane pores, which generally have...
616
01:18Detergent Purification of Membrane Proteins
5.1K
Detergents are used to purify the integral proteins of the membrane. The hydrophobic portion of the detergent can replace membrane phospholipids while solubilizing the membrane proteins. When detergent monomers reach a specific concentration in a solution called critical micelle concentration (CMC), they form micelles. Above CMC, the concentration of the detergent monomers remains in equilibrium with the micelle. The number of detergent monomers present in the CMC varies for each detergent, and...
5.1K
01:06Interfacial Electrochemical Methods: Overview
227
Interfacial electrochemical methods focus on the phenomena occurring at the boundary between an electrode and a solution, as opposed to bulk methods that concentrate on the solution's overall properties. These interfacial methods are classified as either static or dynamic based on the presence of a nonzero current in the electrochemical cell and the consistency of analyte concentrations. Static methods, such as potentiometry, measure the cell's potential without any significant current...
227