Electrochemical Measurement of O2 Permeation Rate through Polymer Electrolyte Membranes

Hydrogen and oxygen permeability through polymer electrolyte membrane are two of the key parameters in membrane characterization, affecting both the fuel cell performance and durability. The O2 crossover rate is usually measured by Gas Chromatography (GC)(1). In this work, we report a novel method that can determine O2 permeation rate by measuring the O2 crossover limiting current across the membrane electrochemically. In this electrochemical O2 permeation rate measurement, humidified O2 is fed to the anode (IrOx electrode), while humidified N2 is fed to the cathode (Pt electrode). The voltage across the cell is imposed by a potentiostat (Fig. 1). The experiment is designed such that the Oxygen Evolution Reaction (OER, Eq. [1]) occurs in the anode (IrOx electrode) and Oxygen Reduction Reaction (ORR, Eq. [2]) occurs in the cathode (Pt electrode)