A Facile and Green Eutectic Salt-Mediated Pyrolysis Strategy to Synthesize Hollow PtNi Alloy Nanocubes for Oxygen Reduction Reaction
Shangyan Zhou, Wei Liao, Zhengcheng Wang, Meida Chen, Jin Long, Qian Zhou, Qingmei Wang
Abstract
The preparation of low-cost, high-activity, and high-stability platinum (Pt)-based oxygen reduction reaction (ORR) catalysts is the key to the large-scale commercial application of proton exchange membrane fuel cells. Herein, we designed a facile synthesis strategy to achieve direct transformation of solid Pt nanoparticles into hollow PtNi alloy nanocubes through a eutectic salt-mediated pyrolysis strategy and nanoscale Kirkendall effect. This distinctive hollow structure makes the inner and exterior spaces easy to access, which would expose additional active sites and a high active surface area. Accordingly, the as-synthesized Pt1Ni8@NC sample, with the moderate Ni feeding content, exhibits an improved ORR activity and stability with respect to a pristine Pt/C catalyst. Such improvement in ORR performance is mainly caused by the moderate surface compositions, high surface area, and well-designed nanostructure. Indeed, this facile surfactant- and template-free synthetic strategy in our work can be extended for fabricating electrocatalysts with a similar hollow cubic structure.