Molybdenum-Enriched Mo_0.5Ru_0.5O₂ Nanoparticles for Efficient and Stable Oxygen Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Ruthenium dioxide (RuO2) exhibits high activity for the acidic oxygen evolution reaction (OER).
• Poor long-term stability of RuO2 hinders its practical application in OER.
• Developing stable and active OER catalysts is crucial for energy conversion technologies.

Purpose of the Study:

• To synthesize a highly stable and active single-phase Mo0.5Ru0.5O2 nanoparticle catalyst.
• To investigate the effect of molybdenum doping on the OER performance and stability of RuO2.
• To explore a novel synthesis method for advanced OER catalysts.

Main Methods:

• Synthesis of Mo0.5Ru0.5O2 nanoparticles using high-temperature thermal shock treatment under oxygen (HTSO).
• Rapid heating to ≈1200 °C for ≈0.05 s followed by quenching at ≈10^4 °C s^-1.
• Characterization of nanoparticle size, elemental mixing, and electrochemical performance in acidic OER.

Main Results:

• The HTSO method produced uniform ≈10 nm Mo0.5Ru0.5O2 nanoparticles with homogeneous elemental distribution.
• The Mo0.5Ru0.5O2 catalyst achieved an overpotential of 210 mV at 10 mA cm^-2.
• Exceptional stability was demonstrated, maintaining performance over 300 h at 50 mA cm^-2, surpassing pure RuO2.

Conclusions:

• Molybdenum doping effectively enhances the stability and activity of RuO2 for acidic OER.
• The HTSO synthesis method overcomes phase separation issues, enabling stable lattice substitution.
• This approach offers a versatile platform for developing cost-effective and stable doped RuO2 OER catalysts.