TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Process: The step of heating the mixture is carried out at 70-90 degrees C. The step of producing of the catalytic metal particles comprises: adjusting the pH of a mixture to within a range, to obtain a resultant, where the mixture comprises a cation exchange polymer solution and a catalytic metal precursor; heating the resultant within a temperature range; and combining a reducing agent with the heated resultant to reduce the catalytic metal precursor, to obtain the catalytic metal particles. The pH is adjusted to 7-12. The temperature is 70-90 degrees C. Preferred Components: The catalytic metal precursor is chloroplatinous acid, chloroplatinic acid, potassium tetrachloroplatinate, hexachloroplatinic acid, ammonium hexachloro ruthenate complex ((NH4)2(RuCl6) or (NH4)2(RuCl5H2O)), gold tetrachloride complexes ((H2(AuCl4)) or (NH4)2(AuCl4)), tetranitrato gold complex (H(Au(NO3)4)H2O) and/or ruthenium (III) chloride. The content of the catalytic metal precursor included in the catalytic metal precursor containing solution is 0.1-100 mg/ml. The catalyst support is Vulcan (RTM: Carbon black), Ketjen black (RTM: Carbon black), acetylene black, an activated carbon powder, a carbon molecular sieve, carbon nanotubes, an activated carbon having micropores and/or a mesoporous carbon.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The reducing agent is formaldehyde, formic acid, polyol, hydrazine, sodium borohydride and/or hydrogen gas. The precipitating agent is an acidic solution. The solvent is polyol, alcohol and/or water.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The content of the cation exchange polymer is: 1-10 parts by weight, based on 100 parts by weight of the catalyst support; and preferably 4-40 parts by weight, based on 100 parts by weight of the catalytic metal precursor. The cation exchange polymer is perfluorocarbon sulfonic acid cation exchange resin, a sulfonated polyimide, a sulfonated polyetherketone, sulfonated polystyrene and/or a sulfonated polysulfone. The pH of the mixture is 7-12. EXAMPLE - Ethanol (10 ml) was placed in a flask (250 ml) and 5 wt.% of Nafion (RTM: Sulfonated tetrafluoroethylene based fluoropolymer-copolymer) solution (133 mg) was added to it. Then, hexachloroplatinic (IV) acid aqueous solution in ethylene glycol (8.1 ml) was added, followed by the addition of sodium hydroxide (4.5 ml) solution until a pH of 8 had been reached. After stirring for 30 minutes, the mixture was heated to 80 degrees C. Formaldehyde solution in alcohol (7 ml) was added dropwise and stirred, and then cooled to room temperature. Vulcan XC-72 (RTM: Carbon black) (90 mg) was added to the obtained mixture and homogeneously mixed by stirring. After adding 1.5 M hydrochloric acid aqueous solution (9.1 ml) as a precipitating agent, the mixture was stirred for 6 hours, then filtered and washed with deionized water. The resultant was dried in an oven at 70 degrees C to obtain platinum/carbon particles (40 wt.%) having average particle size of 2.5-3 nm.