Platinum nanoparticles supported on nitrogen-containing carbon nanofibers (10% Pt/N-CNFs, [N]=0-7.5 wt.%) were synthesized and investigated. X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM) demonstrated the formation of 2-9 nm platinum nanoparticles on the N-CNF surface. Platinum nanoparticles were found to be in a metal state experiencing a strong effect of N-CNFs. Testing of catalytic activity in CO oxidation showed that a nitrogen content in N-CNFs exceeding 3.4 wt.% substantially enhances the low-temperature activity characterized by a reaction ignition temperature of ca. 60 degrees C; however, the enhancement of catalytic activity is non-monotonic with respect to nitrogen concentration in N-CNFs. (C) 2011 Elsevier B. V. All rights reserved.