Proton Relay in Hydrogen-Bond Networks Promotes Alkaline Hydrogen Evolution Electrocatalysis

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The alkaline hydrogen evolution reaction (HER) is crucial for sustainable hydrogen production.
• Water molecule dissociation on electrocatalysts is often limited by unfavorable H/OH delivery.
• Optimizing the orientation of water molecules (O-down vs. H-down) is key to improving HER kinetics.

Purpose of the Study:

• To propose and validate a synergetic water dissociation concept for metal-supported electrocatalysts.
• To enhance the kinetics of the alkaline hydrogen evolution reaction (HER).
• To provide insights for designing advanced bicomponent alkaline HER electrocatalysts.

Main Methods:

• Theoretical profiling of metal-support interface properties and electric fields.
• Fabrication and characterization of cobalt phosphide-supported ruthenium (Ru/CoP) catalysts.
• Electrochemical testing of Ru/CoP catalysts for HER activity.

Main Results:

• A synergetic water dissociation mechanism involving efficient OH and H delivery was proposed.
• A high work function difference (ΔΦ) was identified as crucial for promoting proton relay.
• Ru/CoP catalysts achieved a record-high Ru utilization HER activity of 66.1 A mgRu⁻¹ at -0.1 V vs RHE.

Conclusions:

• The synergetic water dissociation concept effectively overcomes kinetic limitations in alkaline HER.
• The work function difference at the metal-support interface significantly influences catalytic performance.
• This study offers a new avenue for designing highly efficient bicomponent electrocatalysts for alkaline HER.