Effect of Acid Treatment of Graphitized Carbon on Carbon Corrosion in Polymer Electrolyte Membrane Fuel Cells

Pt catalyst was adsorbed on Carbon nanofiber (CNF) by modified polyol method after acid treatment of the carbon support with HNO3 and H2SO4. As the time for acid treatment increases, more oxygen functional groups on carbon surface were produced which improve the loading amount and dispersion of Pt catalyst on carbon supports. In order to inspect the effect of CNF acid treatment time on electrochemical corrosion, constant potential of 1.4 V was applied to a single cell for 30 min and the amount of CO2 emitted was monitored with on-line mass spectrometry. According to the results of our experiment, more CO2 was produced with Pt/oxidized- CNF catalyst in compared to that with unoxidized-CNF. Increasing acid treatment time also induces the more CO2 emission. Besides, performance degradation after corrosion test expanded with severer carbon corrosion. From the observed results, it can be concluded that the acid treatment of CNF is beneficial to catalyst loading, but it also is a significant factor declining the fuel cell durability by accelerating electrochemical oxidation of carbon support.