Revealing the role of mo doping in promoting oxygen reduction reaction performance of Pt3Co nanowires

Abstract

Highly active and durable electrocatalysts towards oxygen reduction reaction (ORR) are imperative for the commercialization application of proton exchange membrane fuel cells. By manipulating ligand effect, structural control, and strain effect, we report here the precise preparation of Mo-doped Pt3Co alloy nanowires (Pt3Co-Mo NWs) as the efficient catalyst towards ORR with high specific activity (0.596 mA cm−2) and mass activity (MA, 0.84 A mg−1Pt), much higher than those of undoped counterparts. Besides activity, Pt3Co-Mo NWs also demonstrate excellent structural stability and cyclic durability even after 50,000 cycles, again surpassing control samples without Mo dopants. According to the strain maps and DFT calculations, Mo dopants could modify the electronic structure of both Pt and Co to achieve not only optimized oxygen-intermediate binding energy on the interface but also increased the vacancy formation energy of Co, together leading to enhanced activity and durability. This work provides not only a facile methodology but also an in-depth investigation of the relationship between structure and properties to provide general guidance for future design and optimization.