Studies On Anode Catalyst Layer In Direct Methanol Fuel Cells

Direct methanol fuel cell (DMFC) is viewed as a promising power source for various portable devices due to its simplicity in structure, convenience in storage and higher energy density of the system. The cell performance strongly depends on the properties of membrane electrode assembly (MEA) which is the"heart"of DMFC. In this thesis, the effects of catalyst layer structures and PtRu black catalyst composition change during treatments in anode on the cell performance were investigated systematically.On the basis of the spraying decal method, the effect of pore formers in the anode catalyst layer on the performance of DMFC was examined and found that under the same catalyst loading, the catalyst layer structure which combined more primary pore volume and moderate secondary pore volume could enhance the single cell performance. Ammonium carbonate (C₂H₁₁N₃O₅) as pore former in the catalyst layer resulted in forming more primary pores and enlarging the electrochemical surface area due to its slowly decomposing manner in the process of thermal treatment. As a result, the maximum output power density was enhanced from 186 mW·cm^-2 to 235 mW·cm^-2, an increasing of 26.3% was achieved under 2 atm oxygen at 80℃.Cyclic voltammetry results showed that the performance of the methanol oxidation reaction (MOR) in anode which the commercial PtRu black was used as catalyst increased when the cyclic scan range window expanded from 0.7V to...