The metal vapor method was used to prepare resin immobilized and active carbon supported Pd Cu bimetallic catalysts with three different Pd/Cu weight ratios.The transmission electron micrograph(TEM) and X ray diffraction(XRD) measurements showed that Pd Cu alloy was formed and the particle sizes of the alloy were very small
with average diameters<5 0nm.The metal particle sizes of resin immobilized catalysts were much smaller than that of active carbon supported catalysts.X-ray photoelectron spectroscopy indicated taht both Pd and Cu were in zero-valent state. The catalytic activities and selectivities of resin immobilized Pd-Cu catalysts in hydrogenation of 4-methy1-3-penten-2-one were much greater than that of the active carbon supported Pd-Cu catalysts.