A new kind of materials that can be applied to a gas chromatographic hydrogen isotope separation system was developed to reduce the amount of Pd-Pt alloy required for making the column and to improve the separation efficiency. Pd and Pt were deposited on -Al2O3 powder by using a barrel sputtering system. Prepared sample powder was characterized from surface morphology, element distributions on the surface, composition and crystallinity. The characterization showed that a uniform layer of Pd-Pt alloy with expected composition was formed on Al2O3 particles. The crystallinity, however, was poor, but improved after annealing at 1073 K for 2 hours. The hydrogen absorbing behavior was also improved by the annealing. A separation column was prepared from the annealed powder and was subjected to experiments on hydrogen isotope separation. The column of annealed powder gave considerably good separation efficiency around room temperature, in spite that only 0.35 g of Pd-Pt was used for the column. The amount of Pd-Pt alloy used here should be compared to previous results, where 1.5 g of Pd-Pt powder was required for high separation efficiency. The new material was quite effective to reduce the amount of Pd-Pt alloy without compromising the separation efficiency and can give further improvement.