SiO2-RuO2: A Stable Electrocatalyst Support

摘要

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 305m~2/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_(Pv), whereas its specific activity was 115 μK 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.