In this study we attempted to obtain a Pd–Pt alloy on alumina (PPA) by using an impregnation and alcohol reduction method for the purpose of a hydrogen isotopes separation, in which α-alumina powder was impregnated into an ethanol water (1/1, w/w) solution containing PdCl 2 , PtCl 2 , and polyvinylpyrrolidone (PVP, MW=10,000). The sample was dried, reduced by hydrogen, and thermally treated at 1073K. Thus, two kinds of PPA (Pd content 17 and 29wt%) were achieved. The produced PPA showed a good crystallinity from the XRD analysis and it exhibited an adequate hydrogen desorption isotherm as a packing material for the separation of hydrogen isotopes. GC columns packed with PPA and Cu powder were used for the separation of a 29.2% D 2 –H 2 gas mixture at 303 and 343K. The experimental result showed a good separation efficiency of the hydrogen isotopes for the GC process. Consequently, the suggested technique for the production of a Pd–Pt alloy on alumina was proven to be successful.