However, the development of practical PEMFC has long been hindered by the short lifetime of membrane electrodes. The sluggish kinetics of the oxygen reduction reaction (ORR), even using the best carbon-supported Pt nanocatalysts, is six orders of magnitude slower than that of the anode. Therefore, developing high-performance cathode catalysts is the key to accelerate the commercialization of PEMFCs. To date, carbon-supported Pt-based nanocatalysts are considered to be the most effective and mass-producible cathode catalysts. However, Ptbased catalysts suffer from oxidative dissolution at potentials higher than 0.8 V vs. RHE, which can cause severe activity degradation. In addition, it is worth noting that the mixed-potential can be as high as 1.5 V during the start/stop process and/or transient condition of the PEMFC, which can aggravate the oxidation of the catalysts. Therefore, there is an urgent need to develop Pt-based nanocatalysts that can maintain activity at higher voltage.