(354d) The Impact of Inorganic Electrocatalyst Surface Ligands on Humidification Requirements in Operating Proton Exchange Membrane Fuel Cells
AIChE Annual Meeting
Tuesday, November 15, 2022 - 1:50pm to 2:10pm
In this work, we address the question of how the interfacial chemistry of electrocatalyst nanoparticles used in electrodes can influence water management in industrial PEMFC. Our work employs both carbon supported and unsupported (carbon free) platinum-bismuth alloy nanoparticles (PtBi NP) since these have been shown to exhibit superior oxygen reduction reaction (ORR) activity and durability in fundamental benchtop investigations. For example, after 10000 potential cycles in accelerated durability testing, the PtBi NP demonstrate no degradation in mass activity, half-wave potential, Tafel slope and electrochemical surface area (ECSA). We employ a unique inorganic redox synthesis scheme to introduce hydrophilic stannous chloride ligands onto the surface of these nanoparticles with a well-characterized structure and charge density. Alloy nanoparticle surface hydrophilicity is shown to be key to optimizing the humidification and performance of an operating low temperature hydrogen-air PEMFC while maintaining durability at 25 cm2 scale.