The use of novel nanocarbon supports-carbon nanofibers (CNF) and amorphous supermicroporous carbons (ASC) for synthesis of platinum cathode catalysts for proton exchange membrane fuel cells (PEMFC) was investigated. Different types of CNF-with "parallel" and "deck of cards" arrangement of graphitic planes and samples of ASC originating from different organic precursors were synthesized and characterized by XRD, electron microscopy and adsorption methods. Platinum catalysts for PEMFC cathodes on different structural types of CNF and one sample of ASC were synthesized and characterized by XRD, electron microscopy, CO adsorption and by studying characteristics of conventional membrane electrode assembly (MEA) cell with a low Pt loading level of 0.02-0.09 mg/cm(2). The MEA testing showed that the Pt cathode catalysts on CNF exhibit inferior performance in comparison with a catalyst on conventional carbon black support Pt/Vulcan XC-72R. The cathode catalyst prepared on ASC support exhibits considerably better output in MEA, compared with Pt/ Vulcan XC-72R even at a lower Pt loading. (c) 2005 Published by Elsevier B.V.