Application of in situ TEM observation in the development of electrocatalysts for PEFCs: Pt/ordered mesoporous carbon with network structure

Abstract We have developed a novel Pt/C electrocatalyst for polymer electrolyte fuel cells (PEFCs) by utilizing an ordered mesoporous carbon with a 3D network structure (nw-OMC). In this study, in situ transmission electron microscopy and scanning transmission electron microscopy measurements were conducted to investigate the structural changes of the nw-OMC support and dispersion behavior of Pt nanoparticles at elevated temperatures under various atmospheres. The results revealed that structural changes of the catalyst significantly depend on both temperature and atmosphere. Notably, under a nitrogen or hydrogen atmosphere at 180 °C, Pt particles within the nanopores migrated to deeper regions, enabling precise control of their positions in the pores. This adjustment optimizes the catalyst structure, contributing to enhanced activity and durability under PEFC operating conditions.