• Title/Summary/Keyword: Electrooxidation

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Nanocomposite Electrodes for Methanol Electrooxidation Fabricated by a Sputtering Deposition Method (직접메탄올 연료전지를 위한 박막형 나노복합 전극구조 분석)

  • Ko, A-Ra;Han, Sang-Beom;Song, You-Jung;Lee, Jong-Min;Kim, Jy-Yeon;Lee, Young-Woo;Park, Kyung-Won
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.403-405
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    • 2009
  • RF-스퍼터링법을 사용하여 메탄올 산화반응을 위해 박막형 전극을 제조하였다. 전극은 텅스텐 탄화물(WC)과 텅스텐 산화물($WO_3$), 그리고 백금(Pt) 타겟을 이용하였으며 그 구조적 특성과 전기화학적 특성을 TEM(Transmission electron microscopy와 CV(Cyclic Voltametry)를 통하여 촉매적 활성을 측정해 보았다. 같은 양의 백금과의 활성을 비교하고 활성을 확인하였다.

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Photo and Electrocatalytic Treatment of Textile Wastewater and Its Comparison

  • Singaravadivel, C.;Vanitha, M.;Balasubramanian, N.
    • Journal of Electrochemical Science and Technology
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    • v.3 no.1
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    • pp.44-49
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    • 2012
  • Electrochemical and photochemical techniques have been proved to be effective for the removal of organic pollutants in textile wastewater. The present study deals with degradation of synthetic textile effluents containing reactive dyes and assisting chemicals, using electro oxidation and photo catalytic treatment. The influence of various operating parameters such as dye concentration, current density, supporting electrolyte concentration and lamp intensity on TOC removal has been determined. From the present investigation it has been observed that nearly 70% of TOC removal has been recorded for electrooxidation treatment with current density 5 mA/$dm^2$, supporting electrolyte concentration of 3 g/L and in photocatalytic treatment with 250 V as optimum lamp intensity nearly 67% of TOC removal was observed. The result indicates that electro oxidation treatment is more efficient than photocatalytic treatment for dye degradation.

Electrooxidation of DL-norvaline at Glassy Carbon Electrode: Approaching the Modified Electrode for Voltammetric Studies of Hydroquinone and Catechol

  • Kamel, Mahmoud M.
    • Journal of Electrochemical Science and Technology
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    • v.5 no.1
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    • pp.23-31
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    • 2014
  • The DL-norvaline was electrochemically oxidized and deposited on the glassy carbon electrode surface using cyclic voltammetry (CV). The modified electrode was examined for electrochemical oxidation of hydroquinone (HQ) and catechol (CC). It exhibited good electrocatalytic ability towards their oxidation and simultaneous determination in a binary mixture using differential pulse voltammetry (DPV). The peak currents were linear to the concentration of HQ and CC, in the range from $5{\mu}M$ to $100{\mu}M$, and $4{\mu}M$ to $140{\mu}M$, respectively. The determination limits(S/N = 3) for HQ and CC were $1{\mu}M$ and $0.8{\mu}M$, respectively. The obtained modified electrode was applied to simultaneous detection of HQ and CC in water sample.

Nanostructured Alloy Electrode for use in Small-Sized Direct Methanol Fuel Cells (소형 직접 메탄올 연료전지를 위한 나노 합금 전극)

  • Park Gyeong Won;Choi Jong Ho;Park In Su;Nam Woo Hyeon;Seong Yeong Eun
    • 한국전기화학회:학술대회논문집
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    • 2003.07a
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    • pp.83-88
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    • 2003
  • PtRu alloy and $PtRu-WO_3$ nanocomposite thin-film electrodes for methanol electrooxidation were fabricated by means of a sputtering method. The structural and electrochemical properties of well-defined PtRu alloy thin-film electrodes were characterized using X-ray diffraction, Rutherford backscattering spectroscopy. X-ray photoelectron spectroscopy, and electrochemical measurements. The alloy thin-film electrodes were classified as follows: Pt-based and Ru-based alloy structure. Based on structural and electrochemical understanding of the PtRu alloy thin-film electrodes, the well-controlled physical and (electro)chemical properties of $PtRu-WO_3$, showed superior specific current to that of a nanosized PtRu alloy catalyst, The homogeneous dispersion of alloy catalyst and well-formed nanophase structure would lead to an excellent catalytic electrode reaction for high-performance fuel cells. In addition, the enhanced catalytic activity in nanocomposite electrode was found to be closely related to proton transfer in tungsten oxide using in-situ electrochemical transmittance measurement.

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A Study on Sol-gel Preparation of Pt-Ru/C Anode Catalysts for Direct Methanol Fuel Cells (솔-젤 합성에 의한 직접 메탄올 연료전지용 고분산 Pt-Ru/C 음극 촉매의 제조)

  • Lee, Kang-Hee;Kim, Il-Gon;Park, Tae-Jin;Suh, Dong-Jin
    • Journal of the Korean Electrochemical Society
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    • v.6 no.1
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    • pp.13-17
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    • 2003
  • Cryogel and aerogel Pt-Ru/C were synthesized by the sol-gel process for the electrooxidation of methanol. From XRD analysis, it was found that the catalysts had highly dispersed Pt-Ru alloys on carbon support although high temperature treatments have been conducted. Electrocatalytic activities of 3 type aerogel catalysts were investigated in half cell experiments by cyclic voltammetry. Among them, Phloroglucinol-Formaldehyde(PF) type catalyst shows the highest activity. From the results of deactivation test for each catalysts, the aerogel catalysts are found to have excellent durability compared with those prepared by colloidal method.

Kinetic Study of the Electrooxidation of Mefenamic Acid and Indomethacin Catalysed on Cobalt Hydroxide Modified Glassy Carbon Electrode

  • Saghatforoush, Lotfali.;Hasanzadeh, Mohammad.;Karim-Nezhad, Ghasem.;Ershad, Sohrab.;Shadjou, Nasrin.;Khalilzadeh, Balal.;Hajjizadeh, Maryam.
    • Bulletin of the Korean Chemical Society
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    • v.30 no.6
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    • pp.1341-1348
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    • 2009
  • Electrocatalytic oxidation of two anti-inflammatory drugs (Mefenamic acid and Indomethacin) was investigated on a cobalt hydroxide modified glassy carbon (CHM-GC) electrode in alkaline solution. The process of oxidation and its kinetics were established by using cyclic voltammetry and chronoamperometry techniques as well as steady state polarization measurements. Voltammetric studies indicated that in the presence of under study drugs, the anodic peak current of low-valence cobalt species increased, followed by a decrease in the corresponding cathodic current. This result indicates that the drugs were oxidized via cobalt hydroxide species immobilized on the electrode surface via an E$\acute{C}$ mechanism. A mechanism based on the electrochemical generation of Co (IV) active sites and their subsequent consumption by the drugs in question was also investigated. The constants rate of the catalytic oxidation of the drugs and the electron-transfer coefficients reported.

CO-Tolerant PtMo/C Fuel Cell Catalyst for H2 Oxidation

  • Bang, Jin-Ho;Kim, Ha-Suck
    • Bulletin of the Korean Chemical Society
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    • v.32 no.10
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    • pp.3660-3665
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    • 2011
  • CO-tolerant PtMo/C alloy electrocatalyst was prepared by a colloidal method, and its electrocatalytic activity toward CO oxidation was investigated. Electrochemical study revealed that the alloy catalyst significantly enhanced catalytic activity toward the electro-oxidation of CO compared to Pt/C counterpart. Cyclic voltammetry suggested that Mo plays an important role in promoting CO electro-oxidation by facilitating the formation of active oxygen species. The effect of Mo on the electronic structure of Pt was investigated using X-ray absorption spectroscopy to elucidate the synergetic effect of alloying. Our in-depth spectroscopic analysis revealed that CO is less strongly adsorbed on PtMo/C catalyst than on Pt/C catalyst due to the modulation of the electronic structure of Pt d-band. Our investigation shows that the enhanced CO electrooxidation in PtMo alloy electrocatalyst is originated from two factors; one comes from the facile formation of active oxygen species, and the other from the weak interaction between Pt and CO.

Electro-Catalytic Oxidation of Amoxicillin by Carbon Ceramic Electrode Modified with Copper Iodide

  • Karim-Nezhad, Ghasem;Pashazadeh, Ali;Pashazadeh, Sara
    • Journal of the Korean Chemical Society
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    • v.57 no.3
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    • pp.322-328
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    • 2013
  • Copper iodide was employed as a modifier for preparation of a new carbon ceramic electrode. For the first time, the catalytic oxidation of amoxicillin (AMX) was demonstrated by cyclic voltammetry, chronoamperometry and amperometry methods at the surface of this modified carbon ceramic electrode. The copper iodide modified sol-gel derived carbon ceramic (CIM-SGD-CC) electrode has very high catalytic ability for electrooxidation of amoxicillin. The catalytic oxidation peak current was linearly dependent on the amoxicillin concentration and the linearity range obtained was 100 to 1000 ${\mu}mol\;L^{-1}$ with a detection limit of 0.53 ${\mu}mol\;L^{-1}$. The diffusion coefficient ($D=(1.67{\pm}0.102){\times}10^{-3}\;cm^2\;s^{-1}$), and the kinetic parameter such as the electron transfer coefficient (${\alpha}$) and exchange current density ($j_0$) for the modified electrode were calculated. The advantages of the modified CCE are its good stability and reproducibility of surface renewal by simple polishing, excellent catalytic activity and simplicity of preparation.

Substituent Effects and Correlations of Electrochemical Behaviors with Molecular Orbital Calculation of Thioxantone DerivativesⅠ

  • 곽경도;서무룡;하광수;백우현
    • Bulletin of the Korean Chemical Society
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    • v.19 no.5
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    • pp.527-530
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    • 1998
  • This paper presents the electrochemistry and molecular orbital (MO) picture of a series of conformationally-restricted thioxantone derivatives. A series of $C_2-substituted$ thioxanthones were examined to probe the electronic influence of the substituent on the electrooxidation and electroreduction sites (i.e., on the electron densities at the 10-and 9-positions), respectively. In the presence of "electrophoric" groups such as C=O and S, characteristic electrochemical reduction and oxidation responses are observed. The electrochemical reaction was diffusion-controlled, because the $I_p/{\upsilon}^{1/2}$ ratio was constant for the anodic and cathodic wave of thioxantone derivatives. These substituent effects are presented in terms of correlations of oxidation (or reduction) potentials with the highest occupied molecular orbital (HOMO), or lowest unoccupied molecular orbital (LUMO) energies, respectively. There is good correlation between energies of the HOMO vs. $E_{pa}^{(+)}$ and energies of the LUMO vs. $E_{pc}^{(-)}$. Frontier Molecular Orbital (FMO) is changed by the functional group of thioxanthones. FMO energy level was offered us the information about the electron transfer direction, and the coefficient of FMO was offered the information about the electron transfer position. Sulfur atom has an important effect on oxidation potential, $E_{pa}^{(+)}$ and the carbonyl carbon has an important effect on reduction potential, $E_{pc}^{(-)}$. Therefore we were appreciated that the contribution of sulfur atom for the $E_{pa}^{(+)}$ and HOMO energies is larger than the contribution of carbonyl group for the $E_{pc}^{(-)}$ and LUMO energies.

Electrochemical Synthesis of 𝛽-Hydroxynitrile by addition of Acetonitrile into Benzyl Alcohol (벤질알코올과 아세토나이트릴의 반응을 통한 𝛽-hydroxynitrile의 전기화학적 합성)

  • Choi, Hyebin;An, Jaun;Kwon, Ki-Young
    • Applied Chemistry for Engineering
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    • v.33 no.4
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    • pp.436-439
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    • 2022
  • 𝛽-Hydroxynitrile and 𝛽-ketonitrile were synthesized by the electrochemical oxidation of benzyl alcohol in an acetonitrile solvent. 𝛽-Hydroxynitrile was prepared by the reaction between benzaldehyde from the oxidation of benzyl alcohol and acetonitrile anion which was produced from the electrochemical reduction of acetonitrile. 𝛽-Hydroxynitrile was finally electrochemically converted into 𝛽-ketonitrile by applying 20 mA of current for 3 h. We demonstrated that 𝛽-hydroxynitrile or 𝛽-ketonitrile syntheses were prepared by electrochemical oxidation of benzyl alcohol with a commonly used Pt electrode at room temperature.