Carbon-CeO2 composite nanofibers as a promising support for a PtRu anode catalyst in a direct methanol fuel cell

Carbon-CeO2 composite nanofibers, (C-CeO2)NF, in which the CeO2 nanoparticles were embedded in the carbon nanofibers, have been fabricated by electrospinning and used as a support for PtRu nanoparticles as the catalyst for methanol oxidation. The parameters affecting the performance of the catalyst layer structure on a glassy carbon electrode (GCE), such as the catalyst loading and the Nafion content in the catalyst layer, have been investigated. The catalyst layer prepared on the GCE with the nanofiber catalyst showed a different activity from that of the nanoparticle catalyst depending on both the loading of the catalyst and the Nafion content. There was an optimum Nafion content, 20 wt%, in the catalyst layer on the GCE for producing a homogenous layer structure. The homogenous layer structure with the nanofiber was obtained at a relatively high catalyst loading between 0.5 and 1.5 mg cm−2. Under the optimum conditions, the catalyst layer with PtRu/(C-CeO2)NF showed a significantly three times higher mass activity for the methanol oxidation and durability than that of the commercial PtRu/C catalyst due to the incorporation of the CeO2 into the catalyst layer.