Hollow-Structure Pt-Ni Nanoparticle Electrocatalysts for Oxygen Reduction Reaction

An electrocatalyst with high oxygen reduction reaction (ORR) activity and high stability during start-stop operation is necessary. In this paper, hollow-structure Pt-Ni electrocatalysts are investigated as ORR catalysts. After synthesis via sacrificial SiO₂ template method, the electrocatalyst exhibits much higher specific activity (1.88 mA/cm²) than a commercial Pt/C catalyst. The mass activity (0.49 A/mg) is 7 times higher than the commercial Pt/C catalyst. The kinetics of the ORR is evaluated using Tafel and K-L plots. It also exhibits a higher durability than commercial Pt/C catalyst during accelerated durability test (ADT). Moreover, the electrocatalyst shows good resistance against accelerated durability test for start-stop, the specific activity and mass activity drops 34.6% and 40.8%, respectively, far better than the commercial catalyst.