Electrocatalysts with high stability and activity play a key role for the commercialization of polymer electrolyte membrane (PEM) fuel cells. Here we present a new electrocatalyst with significantly enhanced stability and activity. First, indium tin oxide (ITO) nanocrystals are directly grown on functionalized graphene sheets forming the ITO-graphene hybrids. Pt nanoparticles are then deposited on ITO-graphene. Transmission electron microscopy images reveal that Pt nanopacrticles are stabilized at Pt-ITO-graphene triple junction points. Periodic density functional theory calculations confirm the thermodynamically favorable formation of Pt-ITO-graphene triple junctions. The new catalyst materials are tested for oxygen reduction for potential applications in PEM fuel cells, and they exhibit over 2× higher durability and high activity, which are attributed to the special triple junction structure, high dispersion of Pt nanoparticles, and prevention of graphene from corrosion by ITO. This work present an excellent model in studying the structure-function relationship of hybrid materials and the knowledge from this study can be easily applied to novel catalysts design.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)