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Revealing Local Coordination-Modulated Oxygen Evolution Reactivity in High-Entropy Layered Double Hydroxides
Sang Heon Han1, Jihoon Kim1, Eunchong Lee1
1Department of Chemistry, College of Natural Sciences, Seoul National University (SNU), Seoul, Republic of Korea.
Small (Weinheim an Der Bergstrasse, Germany)
|July 14, 2026
Summary
High-entropy layered double hydroxides (HE-LDHs) exhibit enhanced oxygen evolution reaction (OER) performance and stability. Precise composition control, particularly Zn coordination, optimizes catalytic activity for industrial applications.
Area of Science:
- Materials Science
- Electrochemistry
- Catalysis
Background:
- Layered double hydroxides (LDHs) are promising electrocatalysts for the oxygen evolution reaction (OER).
- Sluggish kinetics and structural instability limit their industrial application.
- High-entropy materials offer tunable properties for catalysis.
Purpose of the Study:
- To develop high-entropy NiCoZnFeCr-LDHs (HE-LDHs) for improved OER performance.
- To investigate the effect of Fe:Cr ratio and Zn coordination on catalytic activity.
- To elucidate the structure-activity relationships in multicomponent OER catalysts.
Main Methods:
- Synthesis of high-entropy NiCoZnFeCr-LDHs with controlled Fe:Cr ratios.
- Electrochemical characterization of OER performance (overpotential, Tafel slope, durability).
- Operando spectroscopy and Density Functional Theory (DFT) calculations to analyze structural and electronic properties.
Main Results:
- NiCoZnFe0.8Cr0.2-LDH demonstrated superior OER performance (199 mV overpotential at 10 mA cm⁻²).
- Exceptional durability was observed at 1 A cm⁻² for over 1200 hours.
- Operando spectroscopy revealed Ni reconstruction and a significant shift in Zn coordination to tetrahedral.
- DFT calculations confirmed that tetrahedral Zn facilitates the lattice oxygen-mediated mechanism (LOM) by lowering energy barriers.
Conclusions:
- Precisely controlled high-entropy composition in LDHs significantly enhances OER activity and stability.
- Tetrahedral Zn coordination plays a crucial role in optimizing the OER mechanism via LOM.
- This study provides fundamental insights into designing advanced OER electrocatalysts.
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