Preparation of Unique Flower-like Pt-Ni Alloy Catalysts As the Cathode of a PEMFC By Electrodeposition Technique

Abstract

The hydrogen economy can play an important role in the low-carbon economy, and fuel cells technology is an essential part of the hydrogen economy. The proton exchange membrane fuel cell (PEMFC) is one kind of electrochemical reaction device with the advantages of low temperature operation, high conversion efficiency and noiseless, which is expected to widely utilizes in public transportations.The oxygen reduction reaction (ORR) at the cathode is the rate-determining step in PEMFC. To enhance the ORR activity at the cathode, the unique flower-like platinum-nickel binary alloy catalysts were electrodeposited on the commercial carbon cloth by potentiostatic electrodeposition technique, the PtNi alloy effectively improved the oxygen adsorption and desorption paths on the surface. The PtNi alloy catalysts with shorter lattice distance and effects of high-index facets would increase the electrochemical surface area (ECSA) of the catalysts and power density of fuel cell. The samples of the pure platinum and commercial Pt/C catalyst were also prepared as comparison.Morphology, particle size and elemental composition were characterized by SEM, XRD and ICP-MS. In addition, the electrochemical characteristics of the PtNi catalysts were investigated via cyclic voltammetry (CV) and linear sweep voltammetry (LSV) analysis in 0.1 M perchloric acid solution with rotating disk electrode (RDE). In single cell test, the maximum peak power density of PEMFC with homemade PtNi alloy catalyst as the cathode reached 1031 mW/cm2, enhancing about 12% power density, compared to the commercial Pt/C. Figure 1