TiO2–RuO2 electrocatalyst supports exhibit exceptional electrochemical stability

Abstract

Titanium dioxide–ruthenium dioxide (TiO2–RuO2; TRO) powders were prepared in both the hydrous and anhydrous form using a wet chemical synthesis procedure. These materials were characterized by XRD, TEM, and BET. Their electrical conductivity and electrochemical properties such as stability under potential cycling, electrochemical surface area (ECSA), electrocatalytic activity, and fuel cell performance were measured. Anhydrous TiO2–RuO2 (TRO-a) demonstrated exceptional electrochemical stability compared to baseline Vulcan XC-72R carbon when tested using an aggressive accelerated stability test (AST) protocol. The various TRO powders were catalyzed by depositing platinum nanoparticles by an impregnation–reduction method to yield Pt/TRO electrocatalysts. The Pt/TRO-a electrocatalysts had a mass activity of 54 mA mgPt−1 and a specific activity of 284 μA cmPt−2 for the oxygen reduction reaction. Fuel cell polarization data was obtained on membrane electrode assemblies (MEAs) prepared with Pt/TRO and baseline Pt/C electrocatalysts showed that the Pt-TRO-based MEAs exhibited very good performance. The performance obtained was below the Pt/C benchmark, however, further improvements in performance are expected with greater optimization of the Pt particle size and electrode structure.