oxygen reduction reaction on pt/c at the presence of super paramagnetic of fe3o4 nanoparticles for pemfcs

in this paper the role of super paramagnetic iron oxide nanoparticles (spi) on platinum nanoclusters on activated carbon (pt/c) for electrocatalytic oxygen reduction reaction was considered. four composites of pt/c and super paramagnetic iron oxide nanoparticles were prepared with the same total composites weight and different loading of pt/c (1.2, 0.6, 0.4 and 0.3 mg ). the composite attached on a glassy carbon electrode via a thin layer of nafion, that was made by nafion solution . the electrochemical tests were carried out by using conventional three electrode system in sulfuric acid electrolyte at room temperature. cyclic voltammetry, linear sweep voltammetry, rotating disk electrode configuration and chronoamperometry results showed that by decreasing the pt/c loading, electroactive surface area and oxygen diffusion coefficient decreased. also by increasing the fe3o4 nanoparticles in catalyst composite 2-electron pathway for orr surpass from 4- electron pathway. our results showed that in electrode with the same ratio of pt/c and spi has the best utilization of pt for oxygen reduction reaction.