Electrochemically In Situ Formed Active and Stable Surface Gradient Layer on Amorphous Ni-La-S-O Catalyst for...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Seawater electrolysis for hydrogen production faces challenges due to corrosive environments and impurities.
• Developing high-performance hydrogen evolution reaction (HER) electrocatalysts is crucial for efficient seawater electrolysis.

Purpose of the Study:

• To develop novel amorphous Ni-La-S-O materials with enhanced HER performance in alkaline seawater.
• To investigate the in situ electrochemical activation strategy and surface reconstruction mechanisms.

Main Methods:

• Synthesis of amorphous Ni-La-S-O materials.
• In situ electrochemical activation using chronopotentiometry at -2500 mA cm⁻² (CP2500).
• Electrocatalytic performance testing in alkaline seawater and surface characterization.

Main Results:

• Activated Ni-La-S-O catalysts exhibited a stable 5 µm surface gradient layer after 2h activation.
• The optimal activated Ni-La-S-O (6-1) catalyst required low overpotentials (158 mV at 1000 mA cm⁻²) in alkaline seawater.
• The catalyst demonstrated stable operation for over 120h at 1000 mA cm⁻², outperforming commercial Pt/C.

Conclusions:

• In situ electrochemical activation via CP-processing effectively reconstructs the Ni-La-S-O surface, enhancing HER performance.
• The optimized Ni-La-S-O catalyst shows excellent corrosion resistance and electrocatalytic activity for seawater electrolysis.
• This work provides insights into amorphous catalyst optimization and mechanism investigation for hydrogen production.