Tritium aging effects on separation factors in palladium-hydrogen system

The separation factors of the palladium-hydrogen system were experimentally measured at different temperatures ranging from 248 to 303 K after aging for up to 3.5 years by tritium. The results showed a remarkable hydrogen isotope effect in the aged palladium-hydrogen system compared to the raw system. The hydrogen-deuterium separation factor of the palladium-hydrogen system aged by tritium was correlated to temperature and hydrogen/deuterium ratio in the solid phase of palladium hydride. •A decrease of αH-D was observed in aged Pd-H-D system compared to the fresh system.•Temperature and H/D ratio in solid phase affect αH-D in aged Pd-H-D system.•The existence of helium weakens hydrogen isotope effect in aged Pd-H-D system.