Hydrogen isotope separation methods and systems

A method for separating hydrogen isotopes from one another comprising:

• contacting a first side of a separation membrane with a sample, the sample comprising water in an amount of about 0.03 kg/m3 or less, the sample including a first hydrogen isotope and a second hydrogen isotope, the separation membrane comprising a first layer and a second layer, the first layer comprising a crystalline material of from one to about 5 atomic or molecular layers and a metal selected from Groups 8 to 10 of the periodic table, wherein the metal reduces a thermal conduction barrier of the separation membrane, wherein the metal is present in a discontinuous fashion on a surface of the first layer, the second layer comprising a hydrogen ion conductive ceramic;
• heating the separation membrane to a separation temperature of about 200° C. or greater;
• and
• applying a voltage across the heated separation membrane from the first side of the separation membrane to the second side of the separation membrane, the voltage providing a driving force to selectively conduct the first hydrogen isotope across the separation membrane from the first side to the second side, thereby forming a product on the second side of the separation membrane that is enriched in the first hydrogen isotope, a remaining sample on the first side of the separation membrane being enriched in the second hydrogen isotope.