Abstract: Disclosed is a multi-stage hydrogen water isotopic exchange column suitable for use in producing heavy water. It comprises, at each stage, an overlying vapor-and-water contact bed, an underlying catalyst bed and means for collecting the water dripping from the overlying contact bed and guiding to and sprinkling the water on the upper-surface of the vapor-and-water contact bed of the lower adjacent stage.The vapor-and-water contact bed consists of a closely compacted fine network structure, and the water dripping from an overlying contact bed is transferred through the catalyst bed via water channel and is sprinkled over the upper-surface of the vapor-and-water contact bed of the lower adjacent stage. With this arrangement a multi-stage exchange column according to this invention is guaranteed little amount of gas pressure loss and elimination of water splashing which otherwise would be caused by increasing the flow rate of hydrogen gas.

Abstract: A catalyst for concentrating hydrogen isotopes for use in performing hydrogen isotopes exchange between gaseous hydrogen and liquid water, the catalyst comprising a support of porous polytetrafluoroethylene having a total specific surface area of 2 to 80 m.sup.2 /g as a result of mixing therewith 0.5 to 15% by weight of fluorocarbon or a porous styrene polymer or styrene/divinylbenzene copolymer having a specific surface area of at least 150 m.sup.2 /g, and deposited on the support particles of at least one element selected from Group VIII of the Periodic Table. A method for producing a support of porous polytetrafluoroethylene for such catalyst is also disclosed.