Oxygen reduction and hydrogen oxidation reaction on novel carbon supported PdxIry electrocatalysts

Abstract

In the present work Vulcan XC-72 carbon supported Pd, Ir and PdxIry (with x:y atomic ratios of 3:1, 1:1, 1:3) electrocatalysts are thoroughly investigated for the reactions of hydrogen oxidation (HOR) and oxygen reduction (ORR). The catalysts are prepared via a pulse-microwave assisted polyol synhtesis method. The techniques of X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM) are adopted to investigate the elemental composition, the structure, and the morphology of the as prepared electrocatalysts. Their electrocatalytic properties toward HOR and ORR are evaluated by the aid of cyclic voltammetry (CV) and rotating disk electrode (RDE) techniques. It is found that after the addition of even a small amount of iridium, the electrocatalytic activity of pure palladium is enhanced toward both reactions. According to the obtained results the highest HOR and ORR electrocatalytic activity enhancement is exhibited by PdIr (1:1) sample. The order of the electrocatalytic activity is found to be PdIr > PdIr3 > Pd3Ir > Pd > Ir for HOR and PdIr > Pd3Ir > PdIr3 > Pd > Ir for the ORR, respectively. © 2018 Hydrogen Energy Publications LLC