Mesoporous Carbon Supported Catalyst for Heavy Duty Fuel Cells

The interaction between the catalyst and the carbon support is crucial to both the performance and durability of the membrane electrode assembly (MEA) in a polymer electrolyte membrane fuel cell. Local oxygen transport resistance (R O2 ) has shown to be a significant contributor to the overpotential loss in the catalyst layer. 1 Utilizing mesoporous carbon supports has shown to reduce R O2 compared to high surface area carbon and prevent ionomer poisoning of Pt inside the pores. 2 Engineered catalyst supports (ECS) synthesized through templated organic precursor provides improved control of resulting carbon morphology. 3 This work presents a detailed study of the performance and durability of the ECS supported catalyst. Effect of Pt weight percentage on the carbon support, ionomer loading, and the ionomer type on the catalyst performance and durability is presented. Figure 1 shows the performance at beginning of life (BOL) and end of life (EOL) after 90000 cycles, using US DOE’s electrocatalyst protocol, for MEAs with different ionomer loadings. Polarization curve, Pt accessibility through CO stripping, and R O2 from limiting current will be presented are measured at different intervals between BOL and EOL. Characterization of the Pt particle and catalyst layer structure performed at BOL and EOL will also be presented. This study highlights the value of the morphological and electrochemical evaluation to provide detailed insights into the catalyst and mesoporous carbon support interaction. Acknowledgement This research is supported by Technology Readiness Gross Receipts Tax Credit through New Mexico Legislature. This research is supported by U.S. Department of Energy (DOE) Hydrogen and Fuel Cell Technologies Office, through the Million Mile Fuel Cell Truck Consortium (M2FCT). References 1 Kongkanand, A. et al. Journal of Physical Chemistry Letters, 7, (7), 1127-1137, 2016. 2 Ramaswamy, N. et al. Journal of The Electrochemical Society, 167, (6), 064515, 2020. 3 Ramaswamy, N. US DOE Hydrogen and Fuel Cells Program: 2020 Annual Merit Review and Peer Evaluation Report, 2020. Figure 1