Reseachers in IRG-I of the MIT MRSEC have used a new technique called aberration-corrected Scanning Transmission Electron Microscopy to take the first images of individual atoms on and near the surface of platinum and cobalt nanoparticles, which are key catalysts in the creation of eco-friendly energy storage. The Shao-Horn group anticipates that knowing the surface composition of these nanoparticles will help them to design even better energy catalysts.
The team proposes that these combined platinum and cobalt nanoparticles are up to four times more active than platinum alone because the platinum atoms on the surface are constrained by the cobalt atoms underneath. The use of cobalt modifies the interatomic distances between the platinum atoms on the nanoparticle surface, making them more effective in the chemical reactions that are key to fuel cells. This work also bridges the gap between current understanding of electrocatalysis in bulk materials and at the nano-scale.
This research was performed in collaboration with Professor Paulo Ferreira of the University of Texas at Austin and Dr. Larry Allard of Oak Ridge National Laboratory, and was reported in the Sept. 24 online issue of the Journal of the American Chemical Society.
This work was funded in part by the MRSEC Program of the National Science Foundation under Award No. DMR 02-13282.