Self-adhesive high-entropy oxide sub-nanowire monolithic electrocatalysts

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Industrial seawater electrolysis faces challenges with catalyst activity and durability.
• Structural degradation and mechanical instability limit catalyst performance in harsh seawater environments.

Purpose of the Study:

• To develop a novel monolithic catalyst for efficient and durable seawater electrolysis.
• To overcome limitations of structural degradation and mechanical instability in catalyst layers.

Main Methods:

• Synthesis of a self-adhesive high-entropy oxide catalyst with ~1.2 nm sub-nanowires incorporating 14 metal elements.
• Characterization of catalyst adhesion, active sites, and structural integrity under operational conditions.
• Integration of the catalyst into an anion exchange membrane seawater electrolyzer for performance testing.

Main Results:

• The catalyst exhibits low overpotentials (129 mV in KOH, 153 mV in seawater) at 10 mA/cm².
• Achieved continuous operation at 1,000 mA/cm² for over 4,700 hours in KOH and 4,400 hours in seawater.
• The integrated electrolyzer delivered 3,000 mA/cm² at 1.70 V (80°C) and operated for over 3,819 hours at 2,000 mA/cm².

Conclusions:

• The self-adhesive high-entropy oxide sub-nanowire catalyst demonstrates high activity and exceptional long-term durability for seawater electrolysis.
• The catalyst's intrinsic adhesion and stable active sites effectively address structural and mechanical instability issues.
• This advancement offers a promising solution for efficient and robust hydrogen production from seawater.