INFLUENCES OF BOTH CARBON SUPPORTS AND HEAT-TREATMENT OF SUPPORTED CATALYST ON ELECTROCHEMICAL OXIDATION OF METHANOL

The effects of carbon supports for platinum-ruthenium (Pt-Ru) catalyst s on anode performance of direct methanol fuel cells (DMFC) were inves tigated. Good polarization characteristics of the methanol electrode w ere obtained for a Pt-Ru catalyst supported on an acetylene black with high specific surface area and a pore size distribution in the range of 3 to 8 nm. The performance of the methanol electrode increased with the increase in pore volume for the pore size distribution of 3 to 8 nn. Analyses of various carbon blacks and supported catalysts were car ried out with several techniques: N-2 adsorption (Brunauer-Emmett-Tell er (BET) and Barrett-Joyner-Halenda (BJH) methods), CO adsorption, tra nsmission electron microscope, and scanning electron microscope observ ations. The effects of the heat-treating temperature, time, and atmosp here on the polarization curves of the methanol electrodes with the ac etylene black were investigated. The heat-treatment in air at 370 degr ees C improved not only methanol oxidation but the durability of the P t-Ru catalyst.