• Title/Summary/Keyword: cyclic voltammery

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Comparison of Metal Cleaning Effect on Pt Particles Supported on Carbon and Pt Black Observed by NMR, CV, and TEM

  • Han, Kee-Sung;Han, Oc-Hee
    • Journal of the Korean Magnetic Resonance Society
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    • v.6 no.1
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    • pp.38-44
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    • 2002
  • 60% Pt on Vulcan XC-72 with similar Pt sizes to fuel cell grade Pt black was investigated by $\^$13/C nuclear magnetic resonance spectroscopy (NMR), cyclic voltammery (CV), transmission electron microscopy (TEM). Experiments were carried out on electrochemically cleaned samples as well as as-received. The TEM and CV results showed that the average particle sizes were changed by cleaning. However, the chemical shift ($\delta$$\_$G/) of $\^$13/C of $\^$13/CO absorbed on Pt surfaces did not show any appreciable variation with particle size change as did in Pt black. These results indicate that a combination of different analytic techniques is essential to understand the properties of the metal particle catalysts and that the presence of carbon black support strongly influences the NMR data, probably through metal-support interaction.

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Studies on the Electrochemical Properties for Rancidity of Linoleic Acid (리놀산의 산패에 대한 전기화학적 특성 연구)

  • 김우성;이송주
    • The Korean Journal of Food And Nutrition
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    • v.13 no.4
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    • pp.360-364
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    • 2000
  • We studied the degree of rancidity of linoleic acid for the electrochemical redox reaction in time course and the kinetic parameters. The current of the linoleic acid was increased and the potential was shifted to the positive potential when scan rates were faster. The redox reaction of the linoleic acid was proceeding to totally irreversible and diffusion controlled reaction. From these results, diffusion coefficient(D$\_$o/) of linoleic acid was observed to 2.61$\times$10$\^$-6/ ㎠/s in the 0.1 M TEAP/DMF electrolyte solution. Also, exchange rate constant(K$\^$o/) was observed to 9.79$\times$10$\^$-11/ cm/s. The leaving time in air condition was found to affect the rancidity. We predicted that the product was carbonyl compounds.

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Preparation and Electrochemical Characterization of ZrO2/Ti Electrode by ESD Coating Method (ESD 코팅법에 의한 ZrO2/Ti 전극의 제조 및 전기화학적 특성)

  • Kim, Han-Joo;Hong, Kyeong-Mi;Sung, Bo-Kyung;Park, Soo-Gil
    • Journal of the Korean Electrochemical Society
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    • v.11 no.2
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    • pp.95-99
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    • 2008
  • This study has made the electrode that is coated zirconium oxide on the titanium by ESD(Electrostatic spray deposition) coating methode. It has investigated the effects of the etching method of a Ti substrate as the preparation, making of zirconium oxide film and electrochemical characteristics of the electrode that is etched on the titanium. The HCl etching develops a fine and homogeneous roughness on the Ti substrate. Fabrication and material properties of the metal oxide electrode, which is known to be so effective to generate ozone and hypochlorous acid (HOCl) as power oxidant, were studied. A proper metal oxide material is focus zirconium oxide through reference. A coating method to enhance the fabrication reproducibility of the zirconium oxide electrode was used ESD coating method by zirconium oxychloride. Zirconium oxide films on the Ti substrate were tested using SEM, XRD, Cyclic voltammetry.