Effect of Fe content on Pt-Fe/C bimetallic catalyst performance by pulse-microwave assisted chemical reduction

摘要

Pt-Fe/C bimetallic catalyst for proton exchange membrane fuel cells (PEMFCs) was prepared by a pulse-microwave assisted chemical reduction synthesis (PMWSCR) process. The microstructure and morphology of the as-prepared catalysts were characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The electrocatalytic performance was measured by cyclic voltammetry and constant potential polarization method. The results indicate that the PMWSCR is an efficient method for preparing bimetallic catalyst, and the Pt-Fe atomic ratio are of great important on the size and dispersion of Pt nanoparticles, crystal structure, and catalytic performance. When the atomic ratio of Pt/Fe is 1, the metal nanoparticles are uniform and highly dispersed on the surface of carbon support with an average size of 1.8 nm. The electrochemical measurements show that the electrochemical surface area of the catalyst is 61.9 m~2·g~(-1) when the atomic ratio of Pt/Fe is 1, and the catalyst exhibits the superior performance as the cathode catalyst with a power density of 3.3 W·cm~(-2)·mg~(-1).