NOVELTY - A porous platinum-cerium oxide catalyst comprises porous carbon as carrier and platinum-cerium oxide as catalyst activity component where cerium oxide is 5-15 wt.% with respect to the weight of porous carbon cerium oxide and platinum loading is 20-30%.    USE - A porous platinum-cerium oxide catalyst for enhancing poison-defending performance in fuel cells e.g. proton-exchange film fuel cell or direct methanol fuel cell.    ADVANTAGE - A porous platinum-cerium oxide composite catalyst shows more excellent poison-defending performance than normal Vulcan XC-72 carbon-carrying-platinum catalyst.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for the preparation of porous platinum-cerium oxide catalyst comprises: (a) heating and refluxing porous carbon powder in each acetone and thick HO3 liquid for 1-2 hours, filtrating, washing with deionized water until pH is equal to 6 and drying at 100-120 degrees C constant temperature; (b) measuring and setting porous carbon powder in beaker, adding isopropyl alcohol, water and cerous nitrate ammonium liquid, mixing equally in ultrasonic, adding sodium hydroxide liquid making pH equal to 8-9, dipping for 4-6 hours, filtrating after reaction is complete, washing at 70-90 degrees C and drying in vacuum for 10-14 hours; (c) setting the products of (b) in tube furnace and calcining with N2 at 200-400 degrees C for 2-4 hours obtaining porous cerium oxide powder material; (d) setting porous cerium oxide powder material in three-mouth beaker, adding anhydrous alcohol, water and cymene, respectively, mixing equally by ultrasonic, adding 10-25 mM H2platinumCl6 liquid, stirring for 20-40 minutes and adjusting pH to 8-9 by 1 mol/L Na2CO3 liquid obtaining H2platinumCl6 mixing paste containing carbon cerium oxide material; and (e) slowly dropping formaldehyde into mixing paste obtained in step (d), controlling temperature at 55-65 degrees C, ventilating N2 as protecting gas, stirring by ultrasonic, cooling to room temperature after reaction is finished, stopping gas ventilation, filtrating in vacuum, washing with deionized water until no chlorine hydronium is present and drying in vacuum at 70-90 degrees C obtaining porous platinum-cerium oxide composite catalyst.    DESCRIPTION OF DRAWING(S) - The drawing shows XRD measurement of porous platinum-cerium oxide composite catalyst material.