Ultra-Thin RuIr Alloy as Durable Electrocatalyst for Seawater Hydrogen Evolution Reaction

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Efficient hydrogen evolution reaction (HER) catalysts are crucial for sustainable energy, but performance in seawater remains a challenge.
• Existing catalysts often suffer from low activity or instability in corrosive seawater media.

Purpose of the Study:

• To develop highly active and stable RuIr alloy catalysts for seawater electrolysis.
• To investigate the catalytic properties and stability of RuIr alloys in alkaline seawater.
• To elucidate the active sites for HER on RuIr alloys using theoretical calculations.

Main Methods:

• Synthesis of RuIr alloy catalysts via the polyol reduction method.
• Electrochemical evaluation of catalyst performance (overpotential, stability) in alkaline seawater.
• Density Functional Theory (DFT) calculations to identify active sites and reaction mechanisms.

Main Results:

• RuIr alloy catalysts demonstrated superior activity and stability compared to single-metal catalysts in seawater electrolysis.
• The RuIr alloy achieved an overpotential of 75 mV at 10 mA cm⁻², comparable to Pt/C (73 mV).
• Stable operation for 100 hours was observed in alkaline seawater, indicating excellent durability.

Conclusions:

• RuIr alloy catalysts are highly efficient and stable for seawater electrolysis, offering a viable alternative to platinum-based catalysts.
• The enhanced performance is attributed to increased reactive sites and improved solubility resistance of the alloy.
• DFT calculations identified specific Ru and Ir atom sites as key active centers for the hydrogen evolution reaction.