Multiwalled carbon nanotubes (MWNTs) have been synthesized by the pyrolysis of acetylene using hydrogen decrepitated Mischmetal based alloy hydride catalyst. Structural, morphological, and vibrational characterizations have been carried out using X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, high resolution transmission electron microscopy (HRTEM), Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR) spectroscopy. Pt-supported MWNTs (Pt/MWNTs) have been prepared by chemical reduction method using functionalized MWNTs. Composites of Pt/MWNTs and Pt/C in different weight proportions have been used as electrocatalysts for oxygen reduction reaction in proton exchange membrane fuel cell (PEMFC) and the performance on the accessibility of Pt electrocatalysts for the oxygen reduction reaction in PEMFC has been systematically studied. The cyclic voltammetric studies of the electrodes have been performed in order to understand the factors influencing the elecetrocatalytic activity and fuel cell performance and the results have been discussed.