Ge-Doped RuO₂ for Stable and Active Acidic Oxygen Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Proton exchange membrane water electrolysis is key for green hydrogen production.
• Iridium-free electrocatalysts are needed for efficient and stable oxygen evolution reactions (OER).
• Sluggish OER kinetics and poor catalyst stability limit current applications.

Purpose of the Study:

• To develop an active and stable ruthenium-based electrocatalyst for acidic OER.
• To investigate the effect of germanium (Ge) doping on rutile RuO2 nanoparticles.
• To enhance the efficiency and durability of electrocatalysts for water splitting.

Main Methods:

• Synthesis of germanium-doped rutile RuO2 nanoparticles (Ge0.1Ru0.9O2).
• Electrochemical testing including overpotential measurements and long-term stability tests.
• In situ spectroscopic and electrochemical analyses (ATR-SEIRAS, DEMS) and first-principles calculations.

Main Results:

• The optimized Ge0.1Ru0.9O2 catalyst showed an ultralow overpotential (161 mV at 10 mA cm-2) and excellent stability (650 h at 100 mA cm-2 with 0.164 mV h-1 decay).
• Ge doping enhanced structural stability and electronic properties of RuO2.
• Ge dopants facilitated water dissociation and increased surface hydroxyl group accumulation.

Conclusions:

• Germanium doping is an effective strategy to design robust and highly active Ru-based electrocatalysts for acidic OER.
• The study provides insights into non-metallic cation doping and interfacial water dissociation mechanisms.
• This work advances the development of efficient electrocatalysts for green hydrogen production via water electrolysis.