Non-precious metal fuel cell cathode catalyst based on non pyrolyzed polyaniline-Fe-carbon black and polyaniline-Fe-graphene
In this research, polyaniline/Fe/graphene oxide (PANI/Fe/GO) and polyaniline/Fe/carbon black (PANI/Fe/CB) composites were chemically synthesized as cathode catalyst for oxygen reduction reaction. Surface and elemental characterization of the synthesized composites were done using scanning electron microscopy (SEM), Atomic force microscopy (AFM) and energy dispersive X-ray (EDX) analysis. Elemental analysis confirms the Fe metal content of the catalyst. SEM images of PANI presents globular microstructures while GO on the other hand displays sheet-like structure with a height of 0.889 nm based on AFM results. The electrocatalytic activity of the prepared Fe based catalyst composites was evaluated using cyclic voltammetry (CV), linear sweep voltammetry (LSV), and Chronoamperometry in 0.5 M sulfuric acid purged with oxygen for 5 min. Electrochemical characterization shows the electrocatalytic activities of PANI/Fe/CB with a current density of 3.98 mA/cm2 and PANI/Fe/GO with a current density of 7.13 mA/cm2. Chronoamperometric investigations illustrate that Pt/C gave a more stable curve compared to PANI/Fe/GO. In comparison with the commercially available Pt/C catalyst with a current density of 0.99 mA/cm2, it can be seen that the synthesized PANI/Fe/GO and PANI/Fe/CB composites gave higher current densities compared to the commercially available platinum/ carbon (Pt/C) indicating that these catalyst composites could be a promising catalyst for ORR.