Researcher successfully synthesized an impressively active and durable class of electrocatalysts by using the evolution of solid Pt-Ni bimetallic nanocrystals to create nanoframes.
These porous cage-like structures significantly boosted catalytic activity for the oxygen reduction reaction (the splitting of an O2 molecule into two oxygen ions) that are crucial in the performance of fuel cells and other electrochemical applications, the Department of Energy, Office of Science reported.
The innovation could lead to superior electrocatalysts that operate at lower costs. It provides solutions for important criteria in improving these electrocatalysts, such as "high surface-to-volume ratio, three-dimensional surface accessibility to reactants, and optimal precious metal use."
"The material was synthesized by exploiting the structural evolution of platinum-nickel (Pt-Ni) bimetallic nanocrystals into cage-like structures with a self-assembled Pt skin structure on the interior and exterior surfaces," the Department of Energy reported.
The starting material, crystalline PtNi3 nanoparticles, were transformed in a solution of moderate-temperature Pt3Ni nanoframes with surfaces that boast three-dimensional molecular accessibility. Both the exterior and interior of the framework are composed of a Pt-rich skin structure that enhances oxygen reduction activity.
The method led to 36-fold and 22-fold enhancements in mass and specific catalytic activities, respectively. The work will most likely lead to the development of more efficient electrocatalysts for water-splitting reactions and fuel generation.
The findings were published in a recent edition of the journal Science.
