Effect of the catalyst metal content and the carbon support on proton-exchange membrane fuel cells performance and durability

Catalysts based on Pt nanoparticles supported on carbon (Pt/C) are widely used in proton-exchange membrane fuel cell (PEMFC) cathodes. The Pt weight percent (wt%) and the type of carbon used influence the PEMFC performance and durability, but the mechanism of this influence remains poorly understood. Herein, we systematically investigated the effect of catalyst metal content and the type of carbon support on PEMFC performance and durability by employing two types of commercially available Pt/C catalysts. We evaluated the effect of differences in both local and average Pt wt% on both high surface area carbon (HSC) and Vulcan XC72, including durability testing with 30,000 accelerated stress test cycles. The results show that Pt wt% is the main factor controlling durability of Pt/HSC, with local Pt content being more important than average Pt content. Selection of Pt wt% on the HSC support involves a balance between durability (lower wt% better) and performance (higher wt% better). For Pt/Vulcan, durability and performance were found to be less dependent of Pt wt %. These findings can help guide the design of fuel cell electrodes, especially when dealing with the selection of carbon support and Pt wt%.