Regensburg 2025 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 20: Interfaces and Thin Films I

CPP 20.3: Talk

Tuesday, March 18, 2025, 12:15–12:30, H38

DFT Study of Catalyst-Ionomer Interactions in Hydrogen Fuel Cells — •Johanna Weidelt¹, Fabian Tipp¹, Tobias Binninger¹, and Michael Eikerling^1,2 — ¹Theory and Computation of Energy Materials (IET-3), Institute of Energy Technologies, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany — ²Chair of Theory and Computation of Energy Materials, Faculty of Georesources and Materials Engineering, RWTH Aachen University, 52062 Aachen, Germany

Proton exchange membrane fuel cells (PEMFCs) are promising devices for electricity generation from hydrogen. High efficiencies at low temperatures are achieved with platinum (Pt) as catalyst and Nafion as ionomer material. Because of the environmental persistence of the perfluorinated Nafion chains, fluorine-free ionomer materials are searched that maintain PEMFC performance and durability. To this end, the influence of the ionomer on the catalysis of the oxygen reduction reaction (ORR) in the cathode catalyst layer must be considered. Previous studies suggested that interactions between ionomer and Pt surface can compete with the adsorption of oxygenated ORR intermediates and negatively affect the catalytic activity. In this talk, we present a computational study investigating the competitive adsorption of ionomer species and reaction intermediates at a Pt(111) surface using grand-canonical density functional theory simulations. The Pt-adsorbate interaction strength was evaluated and surface phase diagrams were derived from adsorption energies calculated in implicit water environment under constant electrode potential.

Keywords: DFT; Hydrogen; Fuel cell; Platinum; Nafion