Activity Convergence between Continuous- and Pulsed-Deposition NiFe Hydroxide Anodes in Liquid Alkaline Electrolyzers
Liam Twight1, Luigi Osmieri1, Daniel P Leonard1
1Materials Synthesis and Integrated Devices Group (MPA-11), Los Alamos National Laboratory, Los Alamos, New Mexico 87545-1663, United States.
ACS Applied Materials & Interfaces
|July 21, 2026
Summary
Pulsed deposition enhances nickel-iron hydroxide anode activity for oxygen evolution reactions (OER) by improving microstructure. However, this benefit diminishes under electrolyzer conditions, suggesting alternative performance mechanisms.
Area of Science:
- Electrochemistry
- Materials Science
- Catalysis
Background:
- The oxygen evolution reaction (OER) is crucial for electrochemical technologies.
- Nickel-iron hydroxide is a highly active catalyst for alkaline OER.
- Optimizing catalyst microstructure, beyond chemistry, is key to enhancing OER activity.
Purpose of the Study:
- Investigate the benefits of pulsed current deposition versus continuous current deposition for NiFe hydroxide films.
- Determine if pulsed deposition improves OER activity by altering film microstructure.
- Assess the performance retention of pulsed-deposited films under electrolyzer conditions.
Main Methods:
- Fabrication of NiFe hydroxide films using both pulsed and continuous current electrodeposition.
- Characterization of film microstructure, iron content, and redox reversibility.
- Evaluation of OER activity using three-electrode and electrolyzer setups.
Main Results:
- Pulsed deposition densified NiFe hydroxide films and prevented metal ion depletion.
- Pulsed-deposited films exhibited higher Fe content, redox reversibility, and OER activity at the three-electrode level.
- Performance differences between pulsed and continuous deposition converged under electrolyzer conditions.
Conclusions:
- Pulsed current deposition offers microstructural advantages for NiFe hydroxide OER catalysts.
- Electrolyzer conditions can mask the benefits of improved catalyst microstructure.
- Alternative performance-driving mechanisms may dominate under demanding electrolyzer operation.
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