Effect of Alloy Composition on Electrocatalytic Activity of PdAu Core/Pt Shell Nanoparticle Catalysts for Oxygen Reduction Reaction

Abstract

PdAu alloy nanoparticles with different Au contents were prepared on carbon black (Pd 100-x Au x /CB) by bubbling CO as a reducing agent in acetonitrile solution containing Pd(CH 3 COO) 2 and KAuCl 4 . Then the alloy composition of PdAu nanoparticles was controlled by changing the mixing molar ratio of precursors. XRD exhibited that the neighbor interatomic distance was increased with the Au content for Pd 100-x Au x /CB. The electrocatalytic activity for oxygen reduction reaction (ORR) of the Pt shell monolayer-modified Pd 100-x Au x core nanoparticles (Pt/Pd 100-x Au x /CB) was related to the Au content in the core with a volcano curve, which indicated that the ORR activity can be controlled by the core composition. Furthermore, the ORR activity per unit mass at 0.9 V vs. RHE for Pt/Pd 90 Au 10 /CB was ca . 8 times as high as that of commercial Pt/CB.