Multi-walled carbon nanotubes (MWCNTs) based micro-porous layer oil the carbon paper substrates was prepared by in situ growth in a chemical vapor deposition setup. Platinum nanoparticles were deposited on in situ grown MWCNTs/carbon paper by a wet chemistry route at <100 C. The in situ MWC-NTs/carbon paper was initially surface modified by silane derivative to incorporate sulfonic acid-silicate intermediate groups which act as anchors for metal ions. Platinum nanoparticles deposition on the in situ MWCNTs/carbon paper was carried out by reducing platinum (II) acetylacetonate precursor using glacial acetic acid. High resolution TEM images showed that the platinum particles are homogeneously distributed on the outer surface of MWCNTs with a size range of 1-2nm. The Pt/MWCNTs/carbon paper electrode with a loading of 0.3 and 0.5mg Pt cm(-2) was evaluated in proton exchange membrane single cell fuel cell using H-2/O-2. The single cells exhibited a peak power density of 600 and 800 nWcm(-2) with catalyst loadings of 0.3 and 0.5 mg Pt cm(-2), respectively with H-2/O-2 at 80 degrees C. using Nafion-212 electrolyte. in order to understand the intrinsically higher fuel cell performance, the electrochemically active surface area was estimated by the cyclic voltammetry of the Pt/MWCNTs/carbon paper. (C) 2008 Elsevier B.V. All rights reserved.