▎ 摘　　要

NOVELTY - Producing platinum-based alloy catalyst comprises preparing a carbon-based catalyst carrier solution by dispersing the carbon-based catalyst carrier in a polyol, preparing a mixed solution by adding a platinum solution and a transition metal precursor powder to the carbon-based catalyst carrier solution and mixing at 40-100 degrees C, reducing the platinum-based alloy by adding a reducing agent to the mixed solution, and washing and drying the mixture containing the platinum-based alloy. In the reducing step, reducing agent is sodium hydroxide (NaOH), and is reduced by adjusting the input amount of sodium hydroxide (NaOH) to control the particle size of the platinum-based alloy supported on the carbon-based catalyst carrier. USE - The platinum-based alloy catalyst is useful for fuel cell. ADVANTAGE - The method can easily and accurately adjust the amount of the transition metal particles supported on the carbon-based catalyst carrier since the transition metal precursor powder is directly injected into the carbon-based catalyst carrier solution.