• Title/Summary/Keyword: chemical oxidation

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Oxidative Synthesis of Benzoylpteridines from Benzylpteridines by Potassium Permanganate

  • Kim, Yeon Hui;Gang, Yong Han;Baek, Dae Jin
    • Bulletin of the Korean Chemical Society
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    • v.22 no.2
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    • pp.141-144
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    • 2001
  • 6- and 7-Benzylpteridine derivatives have been converted to the corresponding 6- and 7-benzoylpteridines by the oxidation reaction with KMnO4. The newly synthesized compounds have been characterized by pKa determinations, UV, and 1H-NMR spectra.

Analysis of the Microstructure and Oxidation Behavior of Some Commercial Carbon Fibers

  • Kim, Dae-Ho;Kim, Bo-Hye;Yang, Kap-Seung;Bang, Yun-Hyuk;Kim, Sung-Ryong;Im, Hun-Kook
    • Journal of the Korean Chemical Society
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    • v.55 no.5
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    • pp.819-823
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    • 2011
  • The relationship between the microstructure, mechanical properties, and oxidation behavior of pitch-, polyacrylonitrile (PAN)-, and Rayon-based carbon fibers (CFs) has been studied in detail. Three types of carbon fiber were exposed to isothermal oxidation in air and the weight change was measured by thermogravimetric analyzer (TGA) apparatus. After activation energy was gained according to the conversion at reacting temperature, the value of specific surface area and the surface morphology was compared, and the reaction mechanism of oxidation affecting development of pores of carbon fibers was examined. This study will lead to a new insight into the relationship between the microstructure and mechanical properties of carbon fibers.

N3S-ligated Copper(II) Complex Catalyzed Selective Oxidation of Benzylic Alcohols to Aldehydes under Mild Reaction Conditions

  • Dharmalingam, Sivanesan;Koo, Eunhae;Yoon, Sungho;Park, Gyoosoon
    • Bulletin of the Korean Chemical Society
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    • v.35 no.3
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    • pp.715-720
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    • 2014
  • A Cu(II) complex with an three nitrogens and one sulfur coordination environment was synthesized and characterized. Its redox potential was observed at 0.483 V vs. NHE, very similar to that of a Cu-containing fungal enzyme, galactose oxidase, which catalyzes the oxidation of alcohols to corresponding aldehydes with the concomitant reduction of molecular oxygen to water. The Cu(II) complex selectively oxidizes the benzylic alcohols using TEMPO/$O_2$ under mild reaction conditions to corresponding aldehydes without forming any over-oxidation product. Moreover, the catalyst can be recovered and reused multiple times for further oxidation reactions, thus minimizing the waste generation.

Study of CO Oxidation on Well-Characterized Pt-Ru/C Electrocatalysts Having Different Composition

  • Min, Myoung-Ki;Kim, Joo-Hoon;Kim, Ha-Suck
    • Bulletin of the Korean Chemical Society
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    • v.31 no.1
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    • pp.151-156
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    • 2010
  • In this paper, we characterized bimetallic Pt-Ru/C alloy catalysts having four different compositions and compared the catalytic activities of the prepared alloys for CO oxidation. ICP-AES, EDS, XRD, TEM, and XAS were used to investigate the composition, degree of alloying, particle size, and electronic structure of the prepared Pt-Ru/C catalysts. Those results indicated the synthesis of the alloy catalysts with intended composition and uniform size. The electrochemical study of the characterized alloys showed higher catalytic activity for CO oxidation than that of the commercial Pt/C (E-TEK, Inc., 20 wt %) catalyst. Especially, it was shown that the alloy catalyst with Ru composition of 50 atomic % gave the highest catalytic activity for CO oxidation.