The Pd/SDBC catalysts were prepared in order to develop the wet-proofed catalyst for the deuterium exchange reaction between deuterated hydrogen and water vapor. The reactivity of the catalysts for the hydrogen isotope exchange reaction was tested under the boiling point of water. The experiments for the reaction were conducted to compare the efficiency of the Pd/SDBC catalyst with that of the Pd-Pt/SDBC catalysts. The experimentaly results showed that the Pd-Pt/SDBC had higher catalytic activity for the reaction than Pd/SDBC catalyst. In this study, it was found that the catalytic activity of Pd/SDBC catalyst was enhanced by the addition of small amounts of platinum.