Abstract
In this study, Pt nanoparticles are synthesized on partially graphitic carbons, fluorinated or not. They are characterized for their physicochemical properties and oxygen reduction reaction activity, and tested in membrane electrode assemblies in unit proton exchange membrane fuel cell (PEMFC) cathodes; the results are compared with those of a benchmark TEC10EA40E (R) commercial electrocatalyst based on a low surface area highly-graphitized carbon. The home-made membrane electrode assemblies (MEAs) show performances approaching those of the commercial standard. The effect of the surfacic fluorination of the carbon is neither positive nor negative for the "load-cycling" protocol (benchmark MEAs optimized with the commercial electrocatalyst are more durable than non-optimized MEAs prepared with the two home-made electrocatalysts). In opposition, the fluorinated carbon-based electrocatalyst is the more durable in the AST mimicking repeated "start/stop" operation, at least in terms of electrochemical area loses. This demonstrates that carbon corrosion can be (at least partially) mitigated/slowed-down for a partially-fluorinated carbon versus the non-fluorinated substrate, leaving hope to enhance the durability of PEMFC cathodes for automotive applications. This study further demonstrates that the fate of (fluorinated) carbon-supported Pt nanoparticles may differ when the materials are operated in polymer versus liquid electrolyte.