SiO₂-RuO₂: a stable electrocatalyst support

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing durable and active electrocatalyst supports is crucial for advancing fuel cell technology.
• Traditional carbon supports like Vulcan XC-72R suffer from poor electrochemical stability under aggressive operating conditions.
• Ruthenium dioxide (RuO₂) offers potential advantages due to its conductivity and catalytic properties.

Purpose of the Study:

• To synthesize and characterize high surface area silicon dioxide-ruthenium dioxide (SiO₂-RuO₂) supports.
• To evaluate the electrochemical stability, activity, and fuel cell performance of platinum nanoparticles deposited on these novel supports.
• To compare the performance of the new supports against a commercial carbon black baseline.

Main Methods:

• Wet chemical synthesis of SiO₂-RuO₂ supports with varying ratios.
• Characterization using X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and Brunauer–Emmett–Teller (BET) analysis.
• Electrochemical measurements including linear sweep voltammetry, accelerated stability testing (AST), and fuel cell performance evaluation.

Main Results:

• The optimal 1:1 mol ratio SiO₂-RuO₂ (SRO-1) exhibited a high BET surface area (305 m²/g) and good electrical conductivity (24 S/cm).
• Pt-doped SRO-1 demonstrated a 10-fold increase in electrochemical stability over Vulcan XC-72R carbon during AST.
• The catalyst showed promising mass activity (54 mA/mg(Pt)) and specific activity (115 μA cm(Pt)⁻²), though fuel cell performance was impacted by ohmic and mass transport losses.

Conclusions:

• SiO₂-RuO₂ supports offer significantly improved electrochemical stability compared to conventional carbon supports.
• The SRO-1 support is a promising material for electrocatalyst applications, particularly in fuel cells.
• Further optimization of the electrocatalyst layer is needed to fully realize the potential of Pt-SRO catalysts in fuel cells.