| Summary: | 碩士 === 國立臺灣科技大學 === 化學工程系 === 98 === This study prepared Au and Pt-deposited Au nanoparticles and their electrochemical CO oxidation activities. Dicarboxy acetone, NaBH4, or alkaline solutions was used to control the prepared gold nanoparticles size when sodium was used as the stabilizer. The Pt deposition was carried out by adding H2PtCl6 at 298K via hydrogen-reduction or spontaneous galvanic reduction over the preformed Au sol.
TEM analysis indicated that Au of 5.1 nm size was obtained by adding 4 mM NaBH4 to the sodium citrate system, that cross-linked Au nanostructure was found when adding 3 mM NH4OH to the NaBH4 system, and that cross-linked Au-Pt nanostructure was found by hydrogen reductuion of H2PtCl6 in the present of 5.1 nm Au sol. By UV-vis, ICP, and XPS analysis, almost all of used precursors were reduced during preparation.
CO-stripping experiment indicated gold nanoparticles can oxidize adsorbed CO to CO2 at 0.4~0.6 V at 25℃ and 1.0 M perchloric acid solution. The Pt-deposited Au nanoparticles show better CO oxidation activity than gold nanoparticles, as indicated by a lower onset potential during CO-stripping experiment and a lower Tafel slope during CO-CV experiment. The results of this study indicated that Pt deposition can improve the electrochemical activities of Au catalysts for CO oxidation reaction in acidic electrolyte.
|
|---|
