| Summary: | 博士 === 國立成功大學 === 化學工程學系 === 89 === Abstract
Nanostructured Pt/Ti ((Pt+Pd)/Ti) electrodes were prepared by the electrophoretic deposition of monodispersed Pt (Pt+Pd) nanoparticles synthesized in reverse micelles. The crystal structures of the obtained electrodes were characterized by XRD, and their electrochemical properties (hydrogen adsorption/desorption, formic oxidation, and methanol oxidation) were investigated by cyclic voltammetry.
It was observed that the electrochemical activity of hydrogen adsorption/desorption (in 1M NaOH solution) of the obtained nanostructured Pt/Ti electrodes was much higher than that of the bulk Pt electrode. With the increase in the heat-treatment temperature, the relative percentage of Pt (100) planes increased and the electrochemical activity of hydrogen adsorption/desorption was reduced due to sintering. In addition, the nanostructured Pt/Ti electrode with unpolished Ti support showed higher electrochemical activity than that with polished Ti support because of less serious sintering.
The electrocatalytic activity of the nanostructured Pt/Ti electrode for the oxidation of formic acid were investigated by cyclic voltammetry in a mixed solution of 0.26M HCOOH and 1.0M HClO4. The effects of heat-treatment temperature and the size of Pt nanoparticles were examined. It was observed that the electrocatalytic activity of the resultant Pt/Ti electrode for the oxidation of HCOOH was much higher than that of bulk Pt electrode. With the increases in the heat-treatment temperature and size of Pt nanoparticles, the electrocatalytic activity of Pt/Ti electrode decreased due to the sintering and the reduction of specific surface area. According to the cyclic voltammetric and XRD analyses, it was suggested that the resultant Pt/Ti electrode had lower percentages of Pt(100) and Pt(111) planes but higher percentage of Pt(110) plane than the bulk Pt electrode. As the heat-treatment temperature increased, both the percentages of Pt(100) and Pt(111) planes increased but the percentage of Pt(110) plane decreased.
The crystal structure of the (Pt+Pd)/Ti electrode was characterized by XRD, and their electrocatalytic activity for the oxidation of methanol was investigated by cyclic voltammetry in a mixed solution of 0.1M CH3OH and 1.0M NaOH. The amount of Pd on the (Pt+Pd)/Ti electrode affects the electrocatalytic activity of the electrode. It was observed that the electrocatalytic activity of the (Pt+Pd)/Ti (surface composition 20 at. % in Pd) electrode for the oxidation of CH3OH was higher than that of the Pt/Ti electrode.
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