Bulk and Surface Dual-Modification for Stabilizing RuO₂ Anode in 2 A cm^-2 PEMWE Operation

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Proton exchange membrane water electrolyzers (PEMWEs) are crucial for hydrogen production.
• Iridium oxide (IrO2) is the standard anode but is expensive and scarce.
• Ruthenium dioxide (RuO2) is a potential alternative but suffers from poor durability.

Purpose of the Study:

• To develop a stable and active RuO2-based anode for PEMWEs.
• To overcome the limitations of Ir-free RuO2 durability at industrial current densities.
• To investigate a dual modification strategy for RuO2 stabilization.

Main Methods:

• Bulk Cr substitution into the RuO2 lattice.
• Surface modification with Si.
• Electrochemical testing in PEMWE at 2 A cm-2 and 1.65 V.

Main Results:

• Cr doping stabilized Ru valence and improved charge transfer.
• Si surface modification protected the catalyst from reconstruction.
• The dual-modified RuO2 anode demonstrated stable operation at 2 A cm-2 and 1.65 V.

Conclusions:

• Dual modification (Cr bulk doping and Si surface treatment) enhances RuO2 anode activity and stability.
• This strategy addresses multifactorial degradation mechanisms in RuO2 anodes.
• The findings offer new avenues for developing cost-effective RuO2-based catalysts for PEMWEs.