| Summary: | 碩士 === 國立清華大學 === 化學系 === 97 === In this thesis we have aimed at the preparation and characterization of nanocomposite electrocatalysts for direct methanol fuel cell (DMFC). We applied mesoporous SBA-15 silica as a hard template to prepare mesoporous CMK-3 carbon, which were then used to prepared polymer/CMK-3 nanocomposites. Pt nanoparticles were then reduced and deposited on the nanocomposites by the colloidal method or alcohol reduction method. Alternatively, metal oxides including TiO2 and CeO2 were added into the nanocomposites, with the attempt to enhance the electroactivity of Pt nanoparticles. The thus prepared nanocomposite materials were characterized by X-ray diffraction, nitrogen physisorption analysis, and thermal analysis. Besides, the electrochemical activities of the Pt-containing nanocomposite catalysts were analyzed by cyclic voltammetry and CO-stripping experiments. The results showed that the catalytic activity got better when using polymer/CMK-3 nanocomposites containing hydrophilic polymers. However, these nanocomposite catalysts also exhibited 40-50% decrease in current density of methanol oxidation at 0.8 V after running the half cells for around 30 min. On the other hand, the addition of TiO2 or CeO2 indeed enhance the performance of the Pt-containing nanocomposites, which exhibited higher current density and better stability.
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