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

Authors: Bang-An Lu, Tian Sheng, Na Tian,Zong-Cheng Zhang, Chi Xiao, Zhen-Ming Cao, Hai-Bin Ma, Zhi-You Zhou, Shi-Gang Sun

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 μg_Pt⁻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 PtCuAu_0.0005/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.

Link: http://www.sciencedirect.com/science/article/pii/S2211285517300034