Effect of ceria nanoparticles into the Pt/C catalyst as cathode material on the electrocatalytic activity and durability for low-temperature fuel cell

Abstract

An effective method is developed for preparing highly dispersed CeO2 nanoparticles on a Pt/C catalyst synthesized by a continuous two-step process as a cathode material in low-temperature fuel cell. The XRD patterns of the 20Pt–10CeO2/C catalyst reveal that both crystalline Pt and CeO2 phases coexist. The HR-TEM images show that Pt and CeO2 nanoparticles have average particle sizes of approximately 3.4 nm and 4.2 nm, respectively, with quite a narrow distribution between 3 nm and 5 nm. Based on the analysis of the polarization curves for the ORR, the optimum proportion of CeO2 into the 20Pt/C catalyst is 10 wt%. In the ORR and single cell tests, the 20Pt–10CeO2/C catalyst shows higher performance than the commercial 20Pt/C catalyst, owing to the oxygen storage capacity of CeO2 and its ability to exchange oxygen rapidly with oxygen in the buffer. In the accelerated stability tests, the 20Pt–10CeO2/C catalyst has a better durability compared to the commercial 20Pt/C catalyst due to the existence of CeO2, which prevents the agglomeration and dissolution of Pt nanoparticles on the carbon support, extending the life of the catalyst.