Atomically Engineered RuW@IrRuW Nanocatalysts for Superior Alkaline Hydrogen Oxidation Reactions

Area of Science:

• Electrochemistry
• Materials Science
• Nanotechnology

Background:

• Anion exchange membrane fuel cells (AEMFCs) are hindered by slow kinetics and poor stability of the hydrogen oxidation reaction (HOR).
• Developing efficient, stable, and CO-tolerant electrocatalysts is crucial for advancing AEMFC technology.

Purpose of the Study:

• To engineer a highly active and stable nanocatalyst for the hydrogen oxidation reaction (HOR).
• To investigate the structure-activity-stability relationships of the novel catalyst in AEMFCs.

Main Methods:

• Wet-chemical impregnation and atomic substitution to synthesize RuW@IrRuW nanocatalyst on N-doped hollow carbon nanospheres (NHCSs).
• Electrochemical characterization in 0.1 M KOH to evaluate HOR activity, stability, and CO tolerance.
• Combined experimental and theoretical studies (DFT) to elucidate reaction mechanisms.

Main Results:

• The RuW@IrRuW/NHCSs catalyst achieved mass activity of 3257.57 mA mg⁻¹ and specific activity of 2.85 mA cm⁻², significantly outperforming commercial Pt/C.
• Demonstrated outstanding stability with negligible decay after 40,000 s and superior CO tolerance (85.9% activity after 2,900 s in CO).
• Atomically layered IrRuW shell and NHCS support contribute to dual active sites, optimized electronic structure, and enhanced metal-carrier interactions.

Conclusions:

• The engineered RuW@IrRuW/NHCSs catalyst offers a viable strategy to overcome the activity-stability trade-off in HOR electrocatalysis.
• This work paves the way for efficient, durable, and CO-tolerant AEMFCs.