In Situ Self-Assembled 200 nm-Depth Highly Active Layer Non-Precious Metals Catalyst for Industrial Water...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Nickel-based electrocatalysts are crucial for industrial water electrolysis.
• Dense hydroxyl oxide layers formed during oxygen evolution reaction (OER) hinder catalyst performance by limiting active site accessibility and charge transfer.
• Balancing structural stability and effective charge transfer remains a challenge for these catalysts.

Purpose of the Study:

• To develop an efficient in situ leaching strategy for constructing advanced nickel-based electrocatalysts.
• To engineer a catalyst with a grain boundary-rich structure, high charge transfer ability, and a deep catalytic active layer.
• To improve the performance and stability of catalysts for industrial water electrolysis, including seawater applications.

Main Methods:

• In situ leaching strategy applied to a Fe-doped Ni2Al3/Ni3Al alloy.
• Characterization using in situ Raman spectroscopy, transmission electron microscopy, and X-ray absorption spectroscopy.
• Electrochemical performance testing under industrial water electrolysis conditions and seawater electrolysis.

Main Results:

• Construction of a catalyst with stable sub-nano Ni3Al particles embedded in Ni(Fe)OOH.
• Achieved a low OER overpotential of 212 mV at 10 mA cm−2 with a Tafel slope of 25.0 mV dec−1.
• Demonstrated exceptional stability (>500 h at 500 mA cm−2) and superior performance in seawater electrolysis.

Conclusions:

• The in situ leaching strategy effectively creates a high-performance electrocatalyst with enhanced activity and stability.
• The engineered catalyst's deep porous structure facilitates charge transfer and active site accessibility.
• This approach offers a new pathway for designing advanced industrial catalysts for water electrolysis.