Nanostructured Pt Dispersed on Graphene-Multiwalled Carbon Nanotube Hybrid Nanomaterials as Electrocatalyst for PEMFC

Nanostructured platinum dispersed on functionalized graphene and functionalized multiwalled carbon nanotube [Pt/(f-G-f-MWNT)] hybrid nanomaterials, a unique combination of three-, two, and one-dimensional structures, were used as an electrocatalyst for oxygen reduction reaction (ORR) in proton exchange membrane fuel cell (PEMFC). Electrochemical studies performed on Pt/(f-G-f-MWNT) composite materials by varying the ratio of the composition of f-G and f-MWNT for the investigation of the electrochemical active surface area (ECSA) have resulted in an ECSA as high as 108 m(2)/g for the Pt dispersed on nanocomposite containing equal proportions of f-G and f-MWNT. Polarization graphs for the ORR reaction in PEMFC with Pt/(f-G-f-MWNT) as an electrocatalyst resulted in the best performance of 540 mW/cm(2) for the Pt/(50 wt % f-G + 50 wt % f-MWNT) cathode catalyst, agreeing with the electrochemical active surface area of Pt, due to good accessibility and uniform dispersion of the nanostructured Pt catalyst dispersed on the f-G-f-MWNT catalyst support, making them a suitable electrocatalyst for advanced PEMFC. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3374353] All rights reserved.