Enhancement of the electrocatalytic oxygen reduction reaction on Pd3Pb ordered intermetallic catalyst in alkaline aqueous solutions

Enhancement of the oxygen reduction reaction (ORR) was examined with Pd3Pb ordered intermetallic nanoparticles (NPs) supported on titania (Pd3Pb/TiO2). The Pd3Pb/TiO2 catalyst was synthesized by a conventional wet chemical method with Pd and Pb ion precursors, a reducing agent and TiO2 powder under ambient temperature. X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy measurements indicated the formation of the ordered intermetallic phase of Pd3Pb in the NP form on the TiO2 surface. Electrochemical measurements showed that the Pd3Pb/TiO2 catalyst markedly enhanced the ORR in an alkaline environment due to the unique surface of Pd3Pb NPs and the strong interaction between Pd3Pb and TiO2 compared with TiO2-supported Pd, Pt, and PtPb NPs. The onset potential of Pd3Pb/TiO2 was shifted toward a higher potential by 110-150 mV compared with Pd/TiO2, PtPb/TiO2, and Pt/TiO2. [GRAPHICS] .