Synthesis of a low palladium dosage catalyst and its high performance promoted by Fe2O3 for ethanol electrooxidation

Abstract

In this paper, a low palladium dosage hybrid catalyst (Pd/Fe₂O₃) for ethanol electrooxidation promoted by Fe₂O₃ has been fabricated by a facile solvothermal approach. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) analyses reveal that the prepared face-centered cubic Pd nanoparticles with the average diameter of ca. 5 nm are well dispersed on the surface of the as-prepared dendritic Fe₂O₃. The resulting Pd/Fe₂O₃ hybrid catalyst with a total loading of 8.4 wt% Pd shows higher mass activity (450.8 mA mg⁻¹ Pd) than Pd/XC-72 catalyst (359.9 mA mg⁻¹ Pd) and JM commercial 20% Pt/C catalyst (144.0 mA mg⁻¹ Pt) towards ethanol electrooxidation, and better stability as well. Fe₂O₃ has a promoting effect on oxidizing and removing the adsorbed CO-like intermediate species during electrooxidation of ethanol. These results indicate that due to the low cost and enhanced performance, the Pd/Fe₂O₃ hybrid catalyst may be a superior candidate for direct ethanol fuel cells (DEFCs).