Synthesized Bimetallic Electrocatalyst for Oxygen Reduction Reaction in Polymer Electrolyte Fuel Cells

Abstract

In the present study, a step by step process was applied to synthesize bimetallic electrocatalyst (Ru and Pt on VulcanXC-72R). This process can reduce the amount of platinum and increase the gas diffusion electrode (GDE) performance in the cathodic reaction of polymer electrolyte membrane fuel cells (PEMFCs). Using the impregnation by hydrothermal synthesis method, a series of electrocatalysts with different molar ratios of metals (Pt and Ru) were prepared and applied in the electrode fabrication process. The performance of the electrodes in Oxygen Reduction Reaction (ORR) was studied using electrochemical methods such as, linear sweep voltametery (LSV), electrochemical impedance spectroscopy (EIS), chronoamperometery techniques, and the membrane electrode assembly (MEA). Also, inductive coupled plasma (ICP), X-ray diffraction (XRD), and transmission electron microscopy (TEM) were employed to characterize the synthesized electrocatalysts. The obtained results indicated that the electrocatalyst with 1:1 molar ratio for Pt:Ru enhanced the cathode performance. This can be attributed to the positive effect of Ru on electronic properties of Pt along with the effect of catalyst distribution on the substrate which consequently provides the best three-phase zones.