| Recently, interest in the development of direct methanol fuel cells (DMFCs) has considerably increased due to several advantages of methanol as a fuel compared with hydrogen. However, the low activity of methanol oxidation catalysts, relative to that obtained for hydrogen oxidation, limits DMFC performance.; The objective of my research has been to develop and to characterize novel electro-catalysts for methanol oxidation and oxygen reduction in DMFCs. This has included synthesis and characterization of catalysts, preparation of membrane electrode assemblies (MEAs), and tests of a direct methanol fuel cell.; In previous work by Cheng, it was found that Pt particles on the edge planes were more active than those on the basal planes for electrocatalytic methanol oxidation. These results suggested that carbon fibers with a high density of exposed edge sites would be suitable substrates for electro-catalysts in DMFCs. The edge-abundant vapor grown carbon fibers obtained from MER were chosen for our promised substrates for anode electro-catalysts. The thermal decomposition of organometallic compounds was applied for deposition of Pt and Ru on carbon substrates. The methods for applying catalysts onto carbon electrodes were also studied in order to improve electrode structures.; The effectiveness of the catalysts for the oxidation of methanol and the reduction of oxygen was investigated on single electrode and in complete cells. Surface characterization of catalysts and electrode structures was also performed by using scanning electron microscopy, X-ray diffraction, atomic force microscopy and confocal laser scanning microscopy. |
