Studying the Properties of Membranes for Isotopic Exchange between Hydrogen and Water in Membrane Contact Devices

Results are presented from studying the permeability of Nafion-type perfluorinated sulfonic cation-exchange membranes used in membrane contact devices (MCDs) for chemical isotopic exchange between water and hydrogen. It is shown that the permeability of a perfluorinated sulfonic cation-exchange membrane grows after modifying it with Fe³⁺ ions and subsequent regeneration with a nitric acid solution. The best effect is observed for Nafion 212 membrane (50.8 µm), since its permeability is approximately tripled in the 298–343 K range of temperatures. It is shown that the state of a membrane has no effect on the observed energy of activation. Energy E_a = 14 ± 4 kJ/mol indicates that isotopic exchange is controlled by diffusion processes.