We report a transformative, all inorganic synthesis method of preparing supported bimetallic Pd3Ag alloy nanopartides. The method involves breaking down bulk Pd3Ag alloy into the nanoparticles in liquid lithium, converting metallic Li to LiOH, and transferring Pd3Ag nanoparticles/LiOH mixture onto non-water-soluble supports, followed by leaching off the LiOH with water under ambient conditions. The size of the resulting Pd3Ag nanoparticles was found narrowly distributed around 2.3 nm characterized by transmission electron microscope (TEM). In addition, studies by X-ray diffraction (XRD), extended X-ray absorption fine structure (EXAFS) spectroscopy, and X-ray absorption near edge structure (XANES) spectroscopy showed that the resulting Pd3Ag nanoparticles inherited similar atomic ratio and alloy structure as the starting material. The synthesized Pd3Ag nanoparticles exhibited excellent catalytic activity toward hydrogenation of acrolein to propanal.