Electrocatalytic enhancement of methanol oxidation by graphite nanofibers with a high loading of PtRu alloy nanoparticles

The geometric effect of graphite nanofibers (GNFs) as a support for PtRu electrocatalysts on the oxidation of methanol for direct methanol fuel cells (DMFCs) was studied using X-ray diffraction, field emission transmission electron microscopy (FETEM) and electrochemical measurements. A high loading of 60 wt% PtRu catalyst, which is readily applicable to DMFCs, was well dispersed on GNFs. Further, the shape of the supported metal particles was affected by interactions with the GNFs. Electrochemical analysis indicated that GNF-supported PtRu catalysts resulted in an increased catalytic activity of about 100% over that of Vulcan XC-72 supported catalysts. FETEM data indicate that the enhanced activities result from a geometric modification of the catalyst particles by specific interactions between the GNFs and the supported PtRu nanoparticles. (c) 2006 Published by Elsevier Ltd.