Synthesis and characterization of 20% Pt-Fe/C alloy as a cathode catalyst for oxygen reduction reaction PEMFCs

摘要

Proton exchange membrane fuel cells (PEMFCs) are highly efficient and non-polluting electrical power generators based on two electrochemical reactions. Therefore, PEMFCs are considered to be alternative electricity sources for electric vehicles, portable applications and stationary power systems due to their high power density and eco-friendly environment. However, PEMFCs are associated with many problems for their commercialization such as the high price of electrode catalyst and the slow rate of oxygen reduction reaction (ORR). In this study, two different reducing agents NaBH _4 and HCHO were used in the synthesis of carbon supported Pt-Fe catalysts (Pt-Fe/C-HCHO and Pt-Fe/C-NaBH _4). Both catalysts were characterized using x-ray diffraction (XRD), transmission electron microscopy (TEM) and cyclic voltametry in the range 0.05 -1.2 V vs. SHE. It was observed that reducing agent HCHO is more effective than NaBH _4. In order to reduce amount of platinum, the 20% Pt-Fe/C catalyst was prepared by using Fe. The catalysts were heat treated up to 600 °C for improve the activity and stability. It was found that a temperature of 500 °C yielded the best catalyst morphology and ORR activity at 0.9 V.