Zwitterion-Modified NiFe OER Catalyst Achieving Ultrastable Anion Exchange Membrane Water Electrolysis via Dynamic...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Anion exchange membrane water electrolysis (AEM-WE) is crucial for sustainable hydrogen production.
• Non-precious metal electrocatalysts are needed for industrial AEM-WE.
• Sluggish OH- transfer and H+ accumulation limit AEM-WE performance.

Purpose of the Study:

• To develop an efficient non-precious metal electrocatalyst for AEM-WE.
• To overcome challenges related to ion transfer and performance degradation in AEM-WE.
• To enhance the activity and durability of AEM-WE systems.

Main Methods:

• Synthesis of zwitterion-modified NiFe catalyst (z-NiFe) via gradient soaking.
• In-situ Raman spectroscopy and OH- conductivity measurements.
• Density functional theory (DFT) calculations.
• Electrochemical testing in 1 M KOH and AEM-WE device evaluation.

Main Results:

• The z-NiFe catalyst facilitates rapid OH- transfer, mitigating H+ accumulation.
• An alkaline-enriched surface environment was observed, inhibiting corrosion.
• DFT analysis revealed stabilized adsorbed oxygen and reduced OER overpotential.
• The z-NiFe catalyst exhibited an ultralow Tafel slope (28.5 mV dec-1) and high activity (190 mV at 1,000 mA cm-2).
• The AEM-WE device achieved a low cell voltage (1.76 V at 1,000 mA cm-2) and record durability (>14,000 h).

Conclusions:

• Zwitterion modification effectively enhances OH- transfer and catalytic performance in AEM-WE.
• The z-NiFe catalyst demonstrates significant potential for industrial AEM-WE applications.
• This work represents a major advancement in developing durable and efficient AEM-WE technologies.