Related Experiment Video
Updated: Jun 15, 2026
08:40
Synthesis of Metal Nanoparticles Supported on Carbon Nanotube with Doped Co and N Atoms and its Catalytic Applications in Hydrogen Production
Published on: December 6, 2021
3.8K
Confining High-Valence Iridium Single Sites onto Nickel Oxyhydroxide for Robust Oxygen Evolution
Qun He1, Sicong Qiao1, Quan Zhou1
1National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei 230029, P. R. China.
Nano Letters
|April 22, 2022
Summary
A novel iridium single-atom catalyst stabilized by nickel hydroxide significantly boosts oxygen evolution reaction (OER) performance. This advanced catalyst demonstrates exceptional stability and activity, outperforming commercial iridium oxide in alkaline conditions.
Area of Science:
- Materials Science
- Electrochemistry
- Catalysis
Background:
- Iridium-based catalysts are crucial for the oxygen evolution reaction (OER).
- Improving the activity and stability of these catalysts is a key challenge for practical applications.
- Commercial iridium oxide (IrO2) suffers from dissolution and agglomeration issues.
Purpose of the Study:
- To develop a highly active and stable iridium single-atom catalyst for OER.
- To investigate the structural evolution and active sites of the catalyst under OER conditions.
- To understand the theoretical mechanisms behind the enhanced catalytic performance.
Main Methods:
- Synthesis of a vacancy-rich nickel hydroxide stabilized Ir single-atom catalyst (Ir1-Ni(OH)2).
- Electrochemical testing in alkaline media to evaluate OER activity and stability.
- In situ X-ray absorption spectroscopy (XAS) for structural analysis.
- Density functional theory (DFT) calculations for mechanistic insights.
Main Results:
- The Ir1-Ni(OH)2 catalyst exhibited long-term OER stability exceeding 260 hours.
- Achieved significantly higher mass activity compared to commercial IrO2.
- In situ XAS revealed a reconstructed active structure with high-valence Ir sites coordinated by oxygen ligands on a nickel oxyhydroxide surface.
- Theoretical calculations confirmed the activation of Ir single atoms and identified the OH deprotonation as the rate-determining step.
Conclusions:
- Vacancy-rich nickel hydroxide effectively stabilizes Ir single atoms, preventing dissolution and agglomeration.
- The reconstructed high-valence Ir sites are highly active for OER in alkaline media.
- This work provides a promising strategy for designing advanced, stable, and efficient OER electrocatalysts.
