Induced changes of Pt/C in activity and durability through heat-treatment for oxygen reduction reaction in acidic medium

In this study, the Pt/C catalysts systematically heat-treated from 200 to 800 °C are characterized physically and chemically to investigate the induced properties for the activity and durability. The relative intensity of Pt0 increases from approximately 40 to 70% and the mean Pt particle size mildly increases as the temperature increases from 200 to 600 °C. However, the Pt/C heat-treated at 800 °C sharply increases and shows poor Pt particle size distribution resulting in the poor electrochemical performance. Catalysts prepared at between 200 and 600 °C exhibit similar electrocatalytic properties. Durability tests using sweeping potential between 0.6 and 1.0 V show that the durability of catalysts heat-treated at 400-600 °C significantly increases since the Pt oxide can be readily dissolved under potential cycling as compared to the Pt0. We strongly believe that the induced changes by heat-treatment play an important role in the challenges for fuel cells.