Catalytic Properties of Porous and Faceted Platinum Nanoparticles

Proton exchange membrane fuel cells (PEMFC) have been viewed as candidates for powering zero emissions vehicles and portable devices because of their environmental cleanliness and high efficiency. The efficiency of a PEMFC system is primarily controlled by the slow oxygen reduction reaction at the cathode, which requires an activation voltage drop during normal cell operation. Platinum is widely used as an electrochemical catalyst for the anodic and cathodic reactions, in order to reduce the voltage loss. Unfortunately, using a precious metal catalyst increases the production cost of PEMFC, making them expensive to manufacture. In order to reduce the catalyst loading and increase efficiency, platinum catalysts with greater electrochemically active surface area (EASA) and improved catalytic activity for the rate limiting oxygen reduction reaction are necessary. Application of porous and faceted platinum nanoparticles has the potential to reduce the catalyst loading and improve efficiency, moving the PEMFC closer to commercial production. In this study, porous and faceted platinum nanoparticles will be investigated to determine the EASA and catalytic activity for the oxygen reduction reaction (ORR) using cyclic voltammetry in a rotating disk electrode setup. The platinum particles are also characterized by TEM and XRD analysis. The catalytic properties of each platinum structure will be compared to the performance of fuel cell grade platinum black to determine if they are indeed the key to making the commercial production of PEMFC economically feasible.