Synthesis And Characterization Of Catalysts For Proton Exchange Membrane Fuel Cell

Proton exchange membrane fuel cell (PEMFC) has become a very attractive alternative power source for transportation applications because of its high power density, high energy conversion, high efficiency, and clean utilization. But high cost and low stability are the major problems that hinder the commercialization of PEMFC.This paper we have synthesized Pd-Pt/C composite metal catalyst, with TiO2 doping Pt/C catalysts and core-shell Cu@Pt/C catalyst to enhance the utilization of Pt, reducing catalyst costs and improve the life of the catalyst. More details are presented as following.The Pd-Pt/C composite metal catalyst which we synthesized by chemical reduction has a well crystalline, and the alloy particle size slightly larger than Pt of Pt/C catalyst. Cyclic voltammetry (CV) and rotating disk electrode (RDE) tests showed that the electro catalytic activity of Pd-Pt/C and Pt/C are equivalent, but the utilization of Pt significantly improved.TiO2 nanoparticles was prepared by hydrothermal method with an average particle size of about 7.99nm. The Pt/C catalyst which doped on 10% of TiO2 nanoparticles, performed best catalytic activity and electrochemical stability by CV and RDE tests.A Cu@Pt/C catalyst was synthesized by a two-step reduction method using Vulcan XC-72 as the supporting material. Physical and electrochemical techniques were applied to investigate the structure and performance of the catalyst. X-ray diffraction (XRD) and transmission electron microscopy (TEM) examinations showed that the catalyst has a core-shell structure, the distribution of the catalyst particles is quite uniform, and the particle size ranges from 5 to 6 nm. CV and RDE tests confirmed the high performance of the Cu@Pt/C catalyst with the atom ratio Cu:Pt of 2.73:1, making it a promising low-Pt catalyst for hydrogen fueled PEMFC.When the metal loading up to 40%, the nano-metal particles in the catalyst tendency to agglomerate, and the particle size increases. In this way to the formation of core-shell structure the catalyst with atom ratio Cu:Pt of 1.5:1 has the highest electrochemical activity.