Structural evolution of Pt-based oxygen reduction reaction electrocatalysts

The commercialization of proton exchange membrane fuel cells (PEMFCs) could provide a cleaner energy society in the near future. However, the sluggish reaction kinetics and harsh conditions of the oxygen reduction reaction affect the durability and cost of PEMFCs. Most previous reports on Pt-based electrocatalyst designs have focused more on improving their activity; however, with the commercialization of PEMFCs, durability has received increasing attention. In-depth insight into the structural evolution of Pt-based electrocatalysts throughout their lifecycle can contribute to further optimization of their activity and durability. The development of in situ electron microscopy and other in situ techniques has promoted the elucidation of the evolution mechanism. This mini review highlights recent advances in the structural evolution of Pt-based electrocatalysts. The mechanisms are adequately discussed, and some methods to inhibit or exploit the structural evolution of the catalysts are also briefly reviewed.