Advances and Directions of Ordered Pt‐Based Transition Metal Alloys Supported on Carbon with Different Dimensions for Boosting ORR Catalytic Activity Toward PEMFCs

The high cost and poor durability of carbon‐supported platinum (Pt/C) catalysts are the major bottlenecks hindering the large‐scale implementation of proton exchange membrane fuel cells (PEMFCs). The development of ordered Pt‐based transition metal (PtM, M = Fe, Co, Ni, etc.) alloys with low Pt content is an effective way to solve these problems. Although the ordered PtM alloys can improve their durability compared with disordered ones, annealing at a high temperature of ≈650 °C is always required to overcome the high energy barrier of the disorder‐to‐order phase transition, which in turn causes significant migration and aggregation of nanoparticles. Fortunately, the spatial structures of carbon carriers can limit the sintering and agglomeration of PtM alloys, while the porosity and specific surface area of carbon carriers are conducive to the improvement of ORR catalytic performance. Herein, the latest progresses of ordered PtM alloys supported on carbon with different dimensions for boosting ORR catalytic performance toward PEMFCs are summarized. In particular, the catalytic mechanisms and synthetic strategies of ordered PtM alloys for ORR are discussed. Finally, according to the current development stage and existing shortcomings of these catalysts, the challenges and prospects of PtM alloys for ORR are also proposed.