Abstract:
This work was carried out to prepare PtPd/C electrocatalyst-coated membrane for oxygen reduction reaction in PEM fuel cell. This work was separated into 2 parts. The first part was the comparative studied of catalyst coating procedure on GDL by direct spray and on membrane by direct spray and decal transfer techniques. The preliminary results showed that both Pt/C and PtPd/C electrocatalysts provided the similar tendency. The electrocatalyst-coated membrane with decal transfer technique provided a higher active surface area, current density and power density compared with those prepared by other investigated techniques. The second part was the preparation of PtPd/C electrocatalyst for oxygen reduction reaction in PEM fuel cell via the combined processes of impregnation and seeding techniques. Effects of GDL improvement, concentration of reducing agent, ratio of Pt and Pd and loading of metal on support were explored. The results exhibited that the GDL improvement can enhance the cell performance. The optimum conditions for preparing PtPd/C electrocatalyst were found at the concentration of reducing agent NaBH4 of 0.15 M at the Pt:Pd ratio of 1:1 (by weight) and 40% metal loading on support. At this condition, the PEM fuel cell provided the current density of 745 mA/cm2 at 0.6 V in H2/O2 system. Additionally, the oxygen reduction reaction on PtPd/C electroctalyst followed 4-electron pathway.