Pd decorated Fe/C nanocatalyst for formic acid electrooxidation

One of the most challenging problems for the fuel cells commercialization is the preparation of active, robust, and low-cost electrocatalysts. This work reports a novel electrocatalyst of Pd decorated Fe/C catalyst, donated as Pd-Fe/C, for formic acid electrooxidation. The Pd-Fe/C is prepared by a spontaneous displacement process, and characterized by an array of analytical techniques including transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Cyclic voltammetric and chronoamperometric measurements demonstrated that the activity of Pd-Fe/C (Pd:Fe = 1:5) (5.10 A mg−1) is about 11 times of Pd/C (0.46 A mg−1) at a given potential of 0.227 V vs. SCE for formic acid electrooxidation. The enhanced electrocatalytic activity and stability are attributed to synergistic effect due to the replacement of Fe atoms by Pd atoms in the outer layer of the Fe nanoparticles, resulting in higher propensity of Fe and lower propensity of Pd to surface oxidation to weaken the CO adsorption.