NOVELTY - Gold nanorod/palladium-platinum alloy shell structure comprises a cylindrical gold nanorod inner core and an island-shaped multi-hole palladium-platinum alloy shell coated on an external surface of the inner core. The cylinder gold nanorod has diameter of 15-18 nm and length of 60-70 nm. The palladium-platinum alloy shell has thickness of 2-20 nm.    USE - Gold nanorod/palladium-platinum alloy shell structure used as a catalyst in nitrophenol reduction or in formic acid oxidation (claimed) in direct formic acid fuel cell.    ADVANTAGE - The structure is induced by platinum such that it has stronger capability of catalyzing, higher catalyzing efficiency, stronger capability for preventing carbon monoxide toxicity, and less cost for electrocatalysis and oxidization of formic acid. Further, the structure has simple preparation, is environmental-friendly, and can be used at lower consumption with high efficiency.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of gold nanorod/palladium-platinum alloy shell structure, comprising:    (A) adding tetrachloroauric(III) acid aqueous solution in cetyltrimethylammonium bromide aqueous solution; then adding sodium borohydride aqueous solution with stirring to prepare first mixed solution, in which ratio of cetyltrimethylammonium bromide aqueous solution, tetrachloroauric(III) acid and sodium borohydride is 0.75:0.0025:0.006; continuously stirring the first mixture solution for three minutes; and then heating for 2-5 hours to obtain gold seed crystal solution containing 0.25 mM gold;    (B) sequentially adding tetrachloroauric(III) acid aqueous solution, silver nitrate aqueous solution and sulfuric acid aqueous solution in cetyltrimethylammonium bromide aqueous solution, then adding the gold seed crystal solution to obtain second mixed solution; placing in thermostatic water bath at 37 degrees C for 12-16 hours to obtain nanorod solution, in which mass ratio of cetyltrimethylammonium bromide, tetrachloroauric(III) acid, silver nitrate, sulfuric acid, ascorbic acid, and gold seed is 5:0.025:0.0075:0.5:0.04:0.000015;    (C) purifying the nanorod solution by centrifuging and separating the nanorod solution, and adding controlled amount of deionized water in the purified nanorod solution such that gold concentration in the nanorod solution is 0.5 mM; and    (D) preparing nanorod solution of gold core/palladium platinum island-shaped alloy shell structure, uniformly mixing the purified nanorod solution with chloropalladite solution and potassium platinate solution, adding ascorbic acid solution to obtain third mixed solution, where mass ratio of ascorbic acid, sum of palladium ion in the chloropalladite and platinum ion in potassium chloroplatinate solution to gold nanorod is 16-18:0.16-1.8:1; placing the third mixed solution in thermostatic water bath at 30 degrees C for 5-6 hours to react, then adding cetyltrimethylammonium bromide solution into the third mixed solution to obtain fourth mixed solution, in which the cetyltrimethyl ammonium bromide concentration in the fourth mixture solution is 0.03 mol/L; and then centrifuging and separating the fourth solution.