Fabrication of PtCu and PtNiCu multi-nanorods with enhanced catalytic oxygen reduction activities

• Metallic PtCu and PtNiCu multi-nanorods with 5 nm diameter and 10 nm length were fabricated by a polyol reduction method.
• Copper precursor dependency on the fabrication of both PtCu and PtNiCu nanorods was observed.
• The multi-nanorods were successfully synthesized with CuCl2, Cu(CH3COO)2 and CuSO4 as Cu precursors but not with Cu(NO3)2.
• The multi-nanorods showed 2–5 times enhanced electrocatalytic activities with good stability for ORR than a Pt/C catalyst.

1-D metallic nanomaterials have received much attention from the viewpoints of material functions of shape-controlled nanocrystals and applications to a variety of technologies. Metallic PtCu and PtNiCu multi-nanorods with diameter of about 5 nm and average length of around 10 nm were fabricated by polyol reduction method and characterized by TEM/EDS, XRD, XRF and electrochemical techniques. The multi-nanorods were successfully synthesized with CuCl2, Cu(CH3COO)2 and CuSO4 as Cu precursors but not with Cu(NO3)2, showing precursor dependency on the nanorod fabrication. The fcc alloy-crystal structures were observed with these multi-nanorods, which showed much more enhanced electrocatalytic activities with good stability for oxygen reduction reaction (ORR) than a conventional Pt/C catalyst. The results demonstrate that Pt-based multimetallic nanocrystals are promising candidates for cathode catalysts to develop next-generation polymer electrolyte fuel cells.