Electrodeposition and sputter deposition of platinum nanoparticles on gas diffusion electrodes

The polymer electrolyte fuel cells (PEFCs) have high potentiality for their use in electrical vehicles, electric power production and power for consumer electronic. The PEFC’s gas diffusion electrodes are catalyzed by deposition of Pt nanoparticles on carbon powder. Such particles must be localized on the electrode surface to achieve high electrocatalyst utilization. The traditional techniques for the electrocatalyst deposition (impregnation followed chemical reduction of metal precursors) do not allow a surface localization and therefore it is necessary to deposit high quantity of Pt. By means of electrodeposition (EDP) and sputter deposition (PVD) it is possible to localize the Pt on the electrode surface. In fact, both techniques ensure catalyst will be located only in regions that have access to electrons and protons, and the catalyst loading will be highly reduced. In this work we describe the preparation methods based on the electrochemical and sputter deposition of low-loading Pt nanoparticles on gas diffusion electrodes, as a tool for manufacturing proton-exchange membrane fuel cell (PEMFC) electrodes with improved performance and catalyst utilization vs. commercial chemical deposited platinum. The electrocatalytic performance were tested for methanol oxidation reaction and compared to a commercial Pt/C catalyst. The activity, with Pt loading < 0.02 mg cm-2, highly increased compared to commercial catalyst.