Platinum Nanoplates as Fuel Cell Electrocatalysts.

Pt nanoplates were synthesized by galvanic displacement from Ag nanoplates and tested for performance as oxygen reduction catalysts for fuel cells. The Pt nanoplates exhibit improved specific activity by a factor of 3.7 compared to Pt nanoparticles (Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. = 1000 and 270 Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. for Pt nanoplates and nanoparticles, respectively), which indicates significant potential for future development of nanoplate electrocatalysts. The 2-d extended surface morphology of nanoplates was studied as a strategy to attain bulk material properties in a high surface area nanostructured material. The Pt nanoplates demonstrate more bulk-like properties approaching the specific activity of bulk polycrystalline Pt (Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. = 2300 Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed.) and exceeding that for Pt black (Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. = 840 Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed.). In addition, cyclic voltammetry reveals that the onset of oxide formation on the Pt nanoplates more closely resembles bulk polycrystalline Pt and Pt black as opposed to Pt nanoparticles. Pt nanoplate electrocatalysts synthesized by galvanic displacement highlight and expose a promising new strategy to achieve a class of nanostructured electrocatalysts with enhanced specific activity. [ABSTRACT FROM AUTHOR]