Proton exchange membrane fuel cells (PEMFC) are a promising power conversion technology with low emissions and power outputs that rival that of the internal combustion engines. One of the prevailing problems of PEMFCs is the high cost due to the platinum catalyst needed at both the anode and the cathode. Since most of the losses in performance happen during the oxygen reduction reaction at the cathode, a larger amount of Pt is needed here. Our approach utilizes pulse potential deposition (PPD) of Pt onto carbon electrodes to create platinum nanoparticles containing high surface area to lower the Pt loading. Using PPD, we also alloy Pt with non-precious metals such as cobalt to create Pt-Co nanoparticles, further reducing the loading while still improving the fuel cell performance. An increase in fuel cell performance has been reported using a seeding method accompanied by an increased temperature of a colloidal deposition solution. We are interested in studying how the temperature during electrodeposition influences the size, shape, and distribution of the nanoparticles and how these properties may affect catalytic activity at the cathode and overall fuel cell performance. Preliminary results indicate that raising the temperature of the deposition solution increases the performance of the electrode so much that it outperforms a commercial electrode with predictably less catalyst.