High-Density Cationic Defects Coupling with Local Alkaline-Enriched Environment for Efficient and Stable Water...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Non-noble metal electrocatalysts exhibit limited activity and stability for the oxygen evolution reaction (OER).
• These limitations hinder their application in electrochemical energy conversion systems.

Purpose of the Study:

• To engineer a highly disordered crystal structure of layered double hydroxides (LDHs) as a model electrocatalyst for OER.
• To investigate the role of defects and local environment in enhancing OER performance.

Main Methods:

• Drastic nonequilibrium precipitation approach to synthesize disordered LDHs.
• Integrated experimental and theoretical studies (e.g., defect analysis, electrochemical testing).

Main Results:

• The disordered crystal structure features high-density cationic defects and a local alkaline-enriched environment.
• Ultrafast diffusion of hydroxide ions (OH-) and prevention of active site dissolution were observed.
• High-density cationic defects, particularly di- and multi-cationic types, were identified as active and durable catalytic sites.

Conclusions:

• Crystal structure engineering of LDHs is a promising strategy for developing robust active sites.
• The disordered catalyst demonstrates high-performance oxygen evolution in alkaline solutions.
• This approach offers a pathway to overcome the limitations of non-noble metal catalysts in OER.