Solid-Liquid Interfacial Hydrogen Bond-Mediated Mass Transfer Toward Industrial Water Electrolysis

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Efficient ion migration at the catalyst-electrolyte interface is vital for catalytic processes.
• A key challenge is bridging the gap for optimal ion diffusion, particularly for hydroxide ions.

Purpose of the Study:

• To introduce hydrogen bonds for mediating hydroxide ion diffusion across the catalyst-electrolyte interface.
• To develop a descriptor based on electrostatic potential for designing interfacial hydrogen bond-mediated catalysis.

Main Methods:

• Functionalization of NiCo OOH with various oxyanions to form hydrogen bonds with electrolyte water molecules.
• Utilizing operando spectroscopy to investigate water electrolysis activity and hydroxide concentration.
• Correlating interfacial properties with catalytic performance using electrostatic potential as a descriptor.

Main Results:

• Hydrogen bonds effectively mediated hydroxide ion diffusion.
• Water electrolysis activity and hydroxide concentration showed a volcano-shaped dependence on the functional group's electrostatic potential.
• Sulfate-modified NiCo OOH demonstrated ultralow energy consumption (4.23 kWh m^-3 _H2) in industrial electrolyzers.

Conclusions:

• Electrostatic potential serves as a valuable descriptor for designing interfacial hydrogen bond-mediated catalysis.
• The developed strategy significantly reduces energy consumption in water electrolysis.
• Potential for massive global electricity savings (predicted 16,000 TWh).