Gas Permeation Properties of Solid Polymer Electrolyte (SPE) Membranes

Gas permeation properties for Nafion membranes and their composites were investigated under various conditions. The permeability coefficients of Nafion depended greatly on the water content, the cation form, and the ion‐exchange capacity. The gas permeation rate through a same sample varied with temperature, pressure, and membrane thickness. The permeabilty of hydrogen was about twice as great as that of oxygen. The electrocatalyst plated on the membrane did not serve as a barrier for gas permeation, but the structure of the catalyst layer played an important role in gas permeation during water electrolysis.