Effect of Au and Ru in Au@Pd and Ru@Pd Core@Shell Nanoparticlcs for Direct Formic Acid Fuel Cells

摘要

In this research, the effect of Au and Ru in Au@Pd and Ru@Pd on the electronic perturbation and the formic acid oxidation activity is investigated. Au@Pd/C and Ru@Pd/C core@shell nanoparticles with 2 nm Pd shell are synthesized via a two-step process. The electronic perturbation and electrochemical activity of the nanoparticles are tested through X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV) measurements, respectively. A positive 0.15 eV binding energy shift for Pd 3p_(3/2) relative to that of Pd/C is observed for Au@Pd/C nanoparticles suggesting that there is charge transfer from Pd to Au. In addition, CV results show that the peak current density of Au@Pd/C, Ru@Pd/C, and Pd/C are 2.1 mA/cm~2,1.5 mA/cm~2, and 1.2 mA/cm~2, respectively. Thus, Au@Pd/C presents the highest activity towards FAO, indicating that a charge transfer from Pd to Au leads to formic acid oxidation activity enhancement.