Method for preparing highly dispersed supported platinum catalyst using complex reducing agent

A method for preparing a highly dispersed supported platinum catalyst, which comprises:

• (a) mixing ethylene glycol and sodium borohydride at a mole ratio of 1:0.01 to 1:0.1 at a temperature of 0 to 50° C. for thirty minutes to three hours to prepare a complex reducing agent;
• (b) dispersing a platinum precursor and a carbon support body in a solvent at a mole ratio of 1:9 to 8:2;
• (c) preparing a mixed solution of the platinum precursor, the carbon support body, and the complex reducing agent by mixing the complex reducing agent in the dispersed solvent at a temperature of 0 to 50° C. for thirty minutes to three hours;
• (d) heating the mixed solution of the platinum precursor, the carbon support body, and the complex reducing agent at a temperature of 40 to 80° C. for three to ten hours;
• and
• (e) adding a hydrochloric acid solution to the heat-treated mixed solution of the platinum cursor, the carbon support body, and the complex reducing agent at a volume ratio of 0.5:1 to 2:1 at a temperature of 0 to 50° C. for twenty minutes to two hours.