A self-breathing electrode enabled by interface regulation and gradient wettability engineering for industrial H₂O₂...

Area of Science:

• Electrochemistry
• Materials Science
• Chemical Engineering

Background:

• Conventional gas diffusion electrodes (GDEs) for electrochemical hydrogen peroxide (H₂O₂) production face challenges with catalyst layer (CL) design.
• PTFE-fused encapsulation and disordered pores in traditional CLs impede mass transport and limit the three-phase interface (TPI).

Purpose of the Study:

• To introduce a novel catalyst/binder interface for improved TPI formation in GDEs.
• To elucidate the mechanisms governing TPI formation using advanced analytical techniques.
• To develop a high-performance, stable system for electrochemical H₂O₂ generation.

Main Methods:

• Developed a non-fused particulate-packed catalyst/binder interface.
• Utilized 3D reconstruction and mesoscale lattice Boltzmann method (LBM) analyses to study TPI formation.
• Constructed a hierarchical gradient CL with ordered porosity and tunable wettability.
• Employed multiscale simulations, in-situ breakthrough, and microfluidic experiments.

Main Results:

• Demonstrated capillarity-driven electrolyte displacement and directional H₂O₂ self-transport.
• Achieved stable Faradaic efficiencies >85% at 300 mA cm⁻² for 300 hours.
• Developed a 400 cm² four-unit self-breathing flow-through stack for continuous H₂O₂ generation.
• Confirmed commercial viability for oxygen-free, low-cost H₂O₂ electrosynthesis.

Conclusions:

• The novel GDE design offers a fundamental framework for advanced electrode development.
• The integrated self-breathing H₂O₂ electrosynthesis system represents a significant advancement with commercial potential.
• This approach overcomes limitations of conventional CLs, paving the way for more efficient electrochemical H₂O₂ production.