TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Components: The first electrode has a mass activity at 0.9 V at room temperature verses reversible hydrogen electrode (RHE) of at least 0.13 mA/ mu g of platinum and palladium in the electrode. The first electrode has a specific electrochemically active surface area of at least 35 m2/g of palladium and platinum in the electrode.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The palladium nanocrystals have truncated octahedral shape. The palladium nanocrystals have shape selected from spherical, tetrahedral, octahedral, cubic, truncated cubic, icosahedral and decahedral. The platinum-containing compound is selected from platinum(II) chloride, platinum(IV) chloride, platinum(II) bromide, chloroplatinic acid, sodium tetrachloroplatinate(II), sodium hexachloroplatinate(IV), potassium tetrachloroplatinate(II), potassium hexachloroplatinate(IV), tetraamineplatinum(II) chloride, tetraamineplatinum(II) nitrate, ammonium tetrachloroplatinate(II), ammonium hexachloroplatinate(IV) and platinum(II) acetylacetonate. The palladium-containing compound is selected from palladium(II) chloride, palladium(II) bromide, palladium(II) nitrate, sodium tetrachloropalladate(II), potassium tetrachloropalladate(II), potassium hexachloropalladate(IV), ammonium tetrachloropalladate(II), ammonium hexachloropalladate(IV), palladium(II) acetate, palladium(II) acetylacetonate, palladium(II) hexafluoroacetylacetonate, palladium(II) trifluoroacetate, tetraaminepalladium(II) acetate, bis(acetonitrile)dichloropalladium(II), and bis(benzonitrile)palladium(II) chloride. The palladium nanocrystal has a truncated octahedral shape. The nanostructure comprises platinum (60-99 wt.%). At least two (preferably at least three) platinum nanodendritic branches extend from the palladium nanocrystal. The platinum nanodendritic branch has an average nominal diameter of 1-8 nm. The platinum-palladium nanocrystals have a truncated octahedral shape. Preferred Method: The palladium nanocrystals are formed by reducing a palladium-containing compound with a reducing agent.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The reducing agent is selected from hydrogen, hydrazine, ascorbic acid, formic acid, tartaric acid, sodium borohydride, lithium aluminum hydride, citric acid, sodium citrate, ethylene glycol, diethylene glycol, tetraethylene glycol, polyethylene glycol, alcohol and poly(vinyl pyrrolidone) (preferably ascorbic acid). EXAMPLE - Polyvinyl pyrrolidone (PVP) (105 mg) (molecular weight of 55000), L-ascorbic acid (60 mg), and citric acid (60 mg) were dissolved in deionized water (8 ml) hosted in a three-necked flask and heated to 100 degrees C in air under magnetic stirring. Meanwhile, Na2PdCl4 (57 mg) was dissolved at room temperature in distilled water (3 ml). The aqueous solution of Na2PdCl4 was then rapidly injected into the flask by pipette. The reaction mixture was heated at 100 degrees C in air for 3 hours, and then cooled down to room temperature to give truncated octahedral palladium nanocrystals. The suspension of palladium nanocrystals and aqueous solution (6 ml) of PVP (35 mg) and L-ascorbic acid (60 mg) were added into a 25-mL, three-necked flask. The mixture was heated to 90 degrees C in air under magnetic stirring. K2PtCl4 (27 mg) was dissolved at room temperature in distilled water (3 ml). The aqueous solution of K2PtCl4 was then rapidly injected into the flask by pipette. The reaction mixture was heated at 90 degrees C in air for 3 hours, and then cooled down to room temperature to give palladium-platinum nanostructures.