Enhanced electrocatalytic performance due to anomalous compressive strain and superior electron retention properties of highly porous Pt nanoparticles

The shape and structure of electrocatalysts at the nanoscale level have a decisive effect on their activity and durability in low-temperature fuel cells. Herein, we report the discovery of unexpected structural phenomena in exotic nanostructures: the anomalous compressive strain and superior electron retention properties of highly porous Pt (HP-Pt) nanoparticles synthesized using a weakly interacting organic capping agent, tetradecyl trimethyl ammonium bromide. Even though the particle size of the HP-Pt nanoparticles was much larger than those of commercial electrocatalysts, bond length shortening occurred anomalously, and the downshifted d-band center eventually led to increased oxygen reduction reaction activity. This is because the HP-Pt nanoparticles had a highly porous urchin-like dendritic structure, interestingly in the single-crystalline phase, despite the large particle size. In addition, their electron retention properties were superior to those of commercial samples, which led to drastically enhanced stability against Pt dissolution at high potentials.

We report the discovery of unexpected structural phenomena in exotic nanostructureof highly prorous-Pt (HP-Pt) nanoparticles synthesized with weakly interacting organic capping agents of tetradecyltrimethyl ammonium bromide (TTAB). The anomalous compressive strain and the higher electron retention property are main origins of enhanced activity and durability for electrocatalysts.Figure optionsDownload high-quality image (151 K)Download as PowerPoint slideHighlights
► Highly porous-Pt (HP-Pt) nanoparticles were synthesized with TTAB.
► HP-Pt showed an anomalous compressive strain and a higher electron retention property.
► Such anomalous structural phenomena were the main origin of enhanced activity and durability.