Platinum nanoparticles loading on carbon nanotube, activated carbon, and activated carbon fiber was carried out by impregnation of hexachloro palatinate ion(IV) from hydrogen hexachloto platinate hydrate [H2PtCl6 center dot 5.7H(2)O] dissolved solution without using reduction agents, and heating the hexachloro platinate(IV) impregnated carbons up to 800 degrees C. When the initial platinum content was controlled to 1000 ppm in the solution, the adsorption capacities of hexachloro platinate(IV) on carbon nanotube, activated carbon and activated carbon fiber were 24%, 47%, and 76%, respectively at the equilibrium state. The adsorption isotherm type of hexachloro platinate(IV) on carbon nanotube was two-step linear and quite different from Langmuir model of activated carbon fiber due to the uniformly developed cylindrical pore structure and size distribution. The average platinum particle size on porous carbons was under 2 nm by heating the hexachloro platinate(IV) up to 400 degrees C in spite of non-using reduction agents, while the average size increased due to the agglomeration of some particles by heating them up to 800 degrees C. Therefore, uniformly distributed platinum nanoparticles loading on porous carbons can be obtained from simple impregnation of hexachloro palatinate ion(IV) from solution and heating it up to 400 degrees C. (C) 2008 Elsevier B.V. All rights reserved.