Pt/Carbon Nanofiber Nanocomposites as Electrocatalysts for Direct Methanol Fuel Cells: Prominent Effects of Carbon Nanofiber Nanostructures

摘要

Carbon nanofibers (CNFs) with, different microstructures, including platelet-CNFs (PCNFs), fishbone-CNFs, and tube-CNFs, were synthesized, characterized and evaluated toward methanol oxidation reaction (MOR). The CNFs studied here showed several structures in which various stacked morphologies as well as the ordering of their size and graphite layers can be well controlled. Platinum nanoparticles have been electrodeposited on CNFs surfaces, and their electrocatalytic activities toward MOR have been studied using cyclic voltammetry, chronoamperometry, and linear sweep voltammograms. Morphologies, textural properties, and the crystalline structure of the CNFs supports and catalysts have been characterized with transmission electron microscopy and scanning electron microscopy. The comparative tests conclude that Pt/PCNFs have the best electrocatalytic performance and good stability at room temperature. The high electrocatalytic activity and stability can be attributed to the specific microstructure of PCNFs, which have large numbers of edge-active carbon atoms on the surface of the CNFs as well as synergistic effects between CNFs and platinum nanoparticles. The results suggest that PCNFs are excellent potential candidates as catalyst supports in direct methanol fuel cells.