Dual interfacial engineering of a Chevrel phase electrode material for stable hydrogen evolution at 2500 mA cm^-2

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Industrial water electrolysis requires electrodes with long-term stability at high current densities.
• Gas bubble detachment at high current densities often causes electrocatalyst degradation and performance loss.
• Developing mechanically stable and active electrodes is critical for efficient hydrogen production.

Purpose of the Study:

• To engineer a mechanically stable, all-metal electrode for efficient and durable water electrolysis.
• To investigate the interfacial properties influencing electrocatalyst performance and stability.
• To demonstrate a dual interfacial engineering strategy for gas-involving reactions.

Main Methods:

• In-situ synthesis of a CuMo₆S₈/Cu electrode via reaction between MoS₂ and Cu.
• Electrochemical testing to evaluate hydrogen evolution reaction (HER) performance and stability.
• In-situ total internal reflection imaging and mechanical tests to analyze interfacial forces.

Main Results:

• The CuMo₆S₈/Cu electrode exhibited strong binding at the catalyst-support interface and weak adhesion at the catalyst-bubble interface.
• Achieved a high current density of 2500 mA cm^-2 at a low overpotential of 334 mV.
• Demonstrated stable operation at 2500 mA cm^-2 for over 100 hours, indicating excellent durability.

Conclusions:

• The developed electrode overcomes the limitations of catalyst peeling-off and degradation during high-current density water electrolysis.
• Dual interfacial engineering, optimizing both catalyst-support and catalyst-bubble interactions, is key to enhancing electrode stability and performance.
• This strategy holds promise for constructing high-performance electrodes for various gas-involved electrochemical reactions.