Activity Investigations and Determination of Kinetic Parameters of Pt-Co Electrocatalyst Supported on Graphene-Polyallylamine Nanocomposites in Oxygen Reduction Reaction in Proton Exchange Membrane Fuel cell

In this research nanocomposites of Pt-Co–Polyallylamine-Graphene Nanoplates (Pt-Co/PAA/GNPs) was developed to improve the oxygen reduction reaction activity and stability of commercial Pt/C electrocatalyst. For this purpose, first graphene oxide (GO) as a support material was synthesized according to hamer and affenman method. Then graphene oxide was functionalized with Polyallylamine through cross linking. After that Pt-Co as a catalyst was dispersed on the as prepared support by a novel process polyol synthesis method assisted by microwave. Raman spectroscopy measurements confirmed the graphitic structure of the produced reduced graphene oxide nanoplates. Fourier transform infrared spectroscopy results illustrate the presence of Polyallylamine in the composite. After investigation of the structure, morphology and composition of the prepared electrodes were characterized by X-ray diffraction, Field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy. the catalytic activities of prepared electrodes for the oxygen reduction reaction were evaluated through cyclic voltammetry and linear sweep voltammetry measurements in the oxygen reduction reaction. X-ray diffraction results showed that Pt-Co particles were dispersed on the support with mean particle size of about 11nm. FESEM images showed that the nanosized Pt- Co were successfully dispersed on functionalized graphene oxide nanoplates. The nanoparticles in the film were observed to be uniform spherical objects and well distributed. According to the electrochemical measurements, active electrochemical surface area of 15.42 m2Pt/mgPt with 62% catalyst utilization and the specific and mass activity peak currents as high as of 26.3345 and 1.7078 mA /mgPt was found for Pt-Co/PAA/GNP which is comparable with respect to the Pt/PAA/GNP electrode and commercial one.