Henryʹs Law and the solubilities of reactant gases in the modelling of PEM fuel cells

Proton exchange membrane (PEM) fuel cells have been under development for many years and appear to be the potential solution for many electricity supply applications. Modelling and computer simulation of PEM fuel cells have been equally-active areas of work as a means of developing better understanding of cell and stack operation, facilitating design improvements and supporting system simulation studies. In general, fuel cell models must be able to predict both activation and concentration polarizations at both anode and cathode. Normally these predictions require values of the concentration of the reactant gases (i.e. H2 and O2) at the interface between the catalyst and the electrolyte. Electrolytes of interest could include various dilute acids or polymeric membranes such as Nafion™ so that gas solubilities, in the form of Henryʹs Law constants, could be required for a diverse group of solvents. Published solubility data have been evaluated and a number of Henryʹs Law correlations are proposed.