SiO₂–RuO₂: A Stable Electrocatalyst Support

High surface area SiO₂-RuO₂ (SRO) supports with various SiO₂: RuO₂ ratios were synthesized using a wet chemical method. The supports were catalyzed by depositing platinum nanoparticles on their surface. The synthesized materials were characterized by XRD, TEM, BET, and linear sweep voltammetry to study microstructure and properties. The electrochemical stability, electrochemical surface area, electrocatalytic activity and fuel cell performance were also measured. The optimal 1:1 mol ratio of SiO₂-RuO₂ (SRO-1) possessed a BET surface area of 305 m²/g and an electrical conductivity of 24 S/cm. This SRO support demonstrated 10-fold higher electrochemical stability than Vulcan XC-72R carbon when subjected to an aggressive accelerated stability test (AST) involving 10,000 potential cycles between 1 and 1.5 V. The mass activity of Pt-doped SRO-1 was 54 mA/mg(Pt), whereas its specific activity was 115 μA cm(Pt)⁻². The fuel cell performance obtained with this catalyst was lower, but compared favorably against a commercial Pt/C baseline. Analysis of fuel cell performance data confirmed that the lower fuel cell performance resulted largely from ohmic and mass transport losses within the unoptimized electrocatalyst layer.