Effect of Preparation Conditions of Pt/C Catalysts on Oxygen Electrode Performance in Proton Exchange Membrane Fuel Cells

Supported Pt/C catalyst with 3.2 nm platinum crystallites was prepared by the impregnation—reduction method. The various preparation conditions, such as the reaction temperature, the concentration of precursor H₂PtCl₆ solution and the different reducing agents, and the relationship between the preparation conditions and the catalyst performance were studied. The carbon black support after heat treatment in N₂ showed improved platinum dispersion. The particle size and the degree of dispersion of Pt on the carbon black support were observed by transmission electron microscopy (TEM). The crystal phase composition of Pt in the catalyst was determined by X-ray diffraction (XRD). The surface characteristics of the carbon black support and the Pt/C catalyst were studied by X-ray photoelectron spectroscopy (XPS). The electrochemical characteristics of the Pt/C catalysts were evaluated from current—voltage curves of the membrane electrode assembly (MEA) in a proton exchange membrane fuel cell.