Synthesis and Characterization of Bimetallic PdM Nanoparticles (M =Ag, Cu) Oxygen Reduction Electrocatalysts

摘要

Electrochemical studies on the catalytic activity of bimetallic PdAg and PdCu compounds for the oxygen reduction reaction (ORR) in acid media are presented. The electrocatalytic activity for the ORR was evaluated using cyclic voltammetry (CV) and rotating-disk electrode (RDE) measurements, in a 0.5 M H_2SO_4 electrolyte at 25 ℃. These materials were synthesized through PdCl_2, AgNO_3 and CuCl reductions with NaBH_4 in a THF solution. The synthesized powder electrocatalysts were characterized by powder X-ray diffraction (XRD) and data analyzed with the software MDI jade 5.0. The XRD results show evidence of the alloy particles with 3nm as average sizes. The electrochemical current-potential behavior was compared with the Palladium and Platinum. Kinetics results show that the bimetallic catalysts containing Ag and Cu are more active for the ORR than the Pd pure, and less active than the nanometric Pt.