Au-Cu-M (M = Pt, Pd, Ag) nanorods with enhanced catalytic efficiency by galvanic replacement reaction.

This work reports a general wet-chemistry method to produce Au-Cu-X (X = Pt, Pd, and Ag) trimetallic nanorods using galvanic replacement reaction with Au-Cu nanorods as the templates. The mild conditions, such as low temperature and slow injection of metal precursors, contributed to the slow galvanic replacement reaction and helped keep the rod structure intact. The distribution of Au, Cu and the doping metals was even in the rods as confirmed by elemental mapping. The alloyed trimetallic nanorods showed enhanced catalytic activity for p-nitrophenol reduction after incorporating the third metal. Remarkably, the Au-Cu-Pd and Au-Cu-Pt nanorods show more than an order of magnitude improvement in the mass activities compared to the Au-Cu nanorods. This facile and general synthetic method can be applied to fabricate other multimetallic nanoparticles with varying shapes and compositions.