Octahedral PtCu alloy nanocrystals with high performance for oxygen reduction reaction and their enhanced stability by trace Au

Abstract In fuel cell technologies, the sluggish kinetics of oxygen reduction reaction (ORR) on the cathode is the main obstacle, and it is thus urgent to develop high-performance catalysts. In this work, we have synthesized 10 nm-sized octahedral PtCu alloy nanocrystals by a simple one-pot strategy using I- as shape-directing agent instead of using large surfactants. The area specific activity and mass activity of the synthesized octahedral PtCu/C reach 4.25 mA cm−2 and 1.20 mA μgPt−1 at 0.90 V (vs RHE), respectively, which are 21.3 and 8.6 times higher than those of commercial Pt/C catalysts. Unexpectedly, we found that the stability of PtCu/C can be enhanced dramatically by doping trace Au (Au/Pt =0.0005). The mass activity loss of PtCuAu0.0005/C was only 8%, much smaller than those of PtCu/C (32%), and Pt/C (52%) after 10,000 potential cycles. This study provides a strategic design of Pt-based efficient ORR catalysts for fuel cells.