An Examination of the Catalyst Layer Contribution to the Disparity between the Nernst Potential and Open Circuit Potential in Proton Exchange Membrane Fuel Cells

The dependency of the Nernst potential in an operating proton exchange membrane fuel cell (PEMFC) on temperature, inlet pressure and relative humidity (RH) is examined, highlighting synergistic dependence measured open circuit (OCP) all three parameters. An alternative model equation derived to more appropriately represent PEMFC system where reactant concentration instead considered as activity. Ex situ gas diffusion electrode (GDE) measurements are used examine electrolyte concentration, catalyst surface area composition OCP absence H2 crossover. This supported by single-cell measurements, wherein RH was also investigated. contribution provides clarity parameters that affect practically well further studies into effects particle surrounding environment a promising way improving performance low current density regime.