Platinum–copper nanotube electrocatalyst with enhanced activity and durability for oxygen reduction reactions

Abstract

The activity and the durability of Pt based electrocatalysts constitute the major challenges in the current fuel cell technology. Motivated by the improved activity and ameliorated durability for Pt based cathode catalysts achieved from the compositional and morphological control, respectively, in this paper, a rationally designed, PtCu based, 1-dimensional electrocatalyst was prepared via a facile and scalable procedure. The detailed materials characterization revealed that the as-prepared nanotubes (NTs) were composed of a PtCu alloy bulk and a Pt-enriched surface with downshifted d-band center position. Towards the electrocatalysis of oxygen reduction reaction, PtCu NTs have displayed a distinguished specific activity with more than a 10-fold improvement relative to the commercial catalysts and more than a 3-fold improvement relative to the 2015 DOE technical target (0.72 mA cm_Pt⁻² @ 0.9 V). Meanwhile, PtCu NTs have shown greatly ameliorated durability in the aspects of both ECSA and mass activity compared to Pt/C (40%) and Pt black after a 6000-cycle accelerated durability test.