Surface Hydroxyl Relay Promotes Acidic Water Oxidation.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Ruthenium (Ru) is a potential alternative to iridium (Ir) for proton exchange membrane water electrolysis (PEMWE).
• Ruthenium-based catalysts exhibit poor stability in acidic conditions due to the oxygen evolution reaction (OER).
• Developing stable and active Ru catalysts is crucial for industrial PEMWE applications.

Purpose of the Study:

• To enhance the stability and activity of RuO2 catalysts for PEMWE.
• To investigate the effect of boron (B) doping on RuO2 catalyst performance.
• To explore the mechanism of hydroxyl relay strategy for OER catalysis.

Main Methods:

• Synthesis of boron-doped ruthenium oxide nanosheets (B-RuO2 NS).
• Characterization of catalyst structure and properties.
• Electrochemical testing to evaluate OER activity and stability.

Main Results:

• Boron doping introduced three-coordinate B sites that facilitate hydroxyl group relay.
• B-doped RuO2 NS exhibited an ultralow overpotential of 190 mV at 10 mA cm-2.
• Exceptional stability was achieved: 1600 h at 10 mA cm-2 and 200 h at 1 A cm-2.

Conclusions:

• Hydroxyl relay engineering via boron doping significantly improves RuO2 catalyst performance.
• The B-O-Ru local structure enhances catalyst framework stability and prevents Ru overoxidation.
• This approach offers a viable pathway for developing durable and high-performance Ru catalysts for PEMWE.