Fabrication and performance of Pt/C electrodes for low temperature H2/O2 fuel cells

Pt/C electrodes were fabricated and their performances compared at low temperature in H2/O2 fuel cells with P2O5–SiO2–PWA (phosphotungstic acid) glass membranes. The performance of the electrodes was explored at room temperature and humid conditions. The effects of the Pt/C loading on the electrode performances as well as the effect of the active region of catalyst surfaces were investigated with respect to the electrochemical behavior. The current–voltage profiles and electrochemical behavior were analyzed at 30 °C and 30% relative humidity (RH) with gaseous hydrogen and oxygen fed over anode and cathode sides, respectively. The cell performance was mainly determined by the high conductivity characteristics of the glass membrane and its promoting effect regarding the oxygen reduction reaction. In the fabrication of membrane electrode assemblies (MEAs), a high performance of 30 mW/cm2 could be achieved when utilizing a large surface area of catalyst and 0.15 mg/cm2 of Pt/C loading and by including polytetraflouroethylene (PTFE) and the ionomer Nafion® in the catalyst ink. The effect of the active region of the catalyst surface was investigated with respect to the output during the cell test, and the MEA with a large sized active area of 0.49 cm2 demonstrated superior performances as compared to the other cells. These details were reported and results were discussed.