RuO2•xH2O-TiO2 as Catalyst Support for PEM Fuel Cells

Abstract

Electrocatalytic activities of Pt supported on RuO2•xH2O-TiO2 and anhydrous RuO2-TiO2 were examined. The electrochemically active surface area (ECSA) of Pt/RuO2•xH2O-TiO2 was found to be less than that of Pt/RuO2-TiO2 (3.2m2/g vs. 16.9m2/g), which suggested that RuO2•xH2O interfered with Pt electrocatalytic activity/accessibility. Pt catalytic activity was recovered when Pt/hydrous RuO2-TiO2 was calcined at 450°C, which led to the conversion of hydrous RuO2-TiO2 to anhydrous RuO2-TiO2 as observed from XRD patterns. The BET surface areas of hydrous RuO2-TiO2 and anhydrous RuO2-TiO2 did not change. Converging evidence from CV, XRD and BET analyses confirmed that hydrous RuO2 exhibited lower Pt catalytic activity/accessibility.