• Title/Summary/Keyword: salt catalyst

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Aluminium Salt of Phosphomolybdic Acid Fabricated by Nanocasting Strategy: An Efficient System for Selective Oxidation of Benzyl Alcohols

  • Aliyan, Hamid;Fazaeli, Razieh;Habibollahi, Nasibeh
    • Journal of the Korean Chemical Society
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    • v.56 no.5
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    • pp.591-596
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    • 2012
  • Preparation of $AlPMo_{12}O_{40}$ (AlPMo) salts, supported on mesostructured SBA-15 silica, by the reaction deposition strategy causes the formation of isolated AlPMo nanocrystals inside the nanotubular channels. The remarkable characteristic of the SBA-15 structure is that all the cylindrical pores are connected by some small channels. This makes the whole pore system in SBA-15 three-dimensional. We have used 2D hexagonal SBA-15 silicas as hard templates for the nanofabrication of AlPMo salt nanocrystal. The oxidation of alcohols occurs effectively and selectively with $H_2O_2$ as the oxidant. AlPMo salt nanocrystal was used as the catalyst.

A Study on the Sulfur-Resistant Catalysts for Water Gas Shift Reaction II. Effect of Alkali Metal Salt on the Activity of CoMo Catalyst (황에 저항성을 가지는 수성가스 전환반응 촉매의 연구 II. CoMo 촉매의 활성에 미치는 알칼리 금속염의 영향)

  • Kim, Joon Hee;Lee, Ho In
    • Journal of the Korean Chemical Society
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    • v.42 no.6
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    • pp.696-702
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    • 1998
  • The effect of alkali metal salt on the activity of Co-Mo catalyst which has high resistance to sulfur poisoning for water gas shift reaction(WGSR) was studied. Two groups of catalysts were prepared to investigate the effects of anion and cation in alkali metal salts. For K-doped catalysts made with various potassium salts having different anion, the catalytic activity was explained to depend mainly on the BET surface area. Among the catalysts prepared by various nitrates of alkali metal as precursor, the Li-doped catalyst showed the best activity, and the others did not make significant differences giving relatively low activities. And the change of BET surface area by varying the loading of alkali metal showed a similar trend to that of activity. In this case, the activity was dependent on both BET surface area and the ratio of $Mo^{6+}$ with a tetrahedral coordination symmetry to $Mo^{6+}$ with an octahedral one, $Mo^6+[T]/Mo^{6+}[O]$ value.

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Dehydropolycondensation of Aminopenols under the Catalytic Action of Metallic Chelate Compounds (I) Effects of the Solvents and Characteristics of the Oligomers Obtained (金屬킬레이트化合物의 觸媒作用에 依한 Aminophenol 類의 酸化的 重縮合反應 (Ⅰ) 溶媒의 效果와 生成重合體의 特性)

  • Choi, Kyu-Suck
    • Journal of the Korean Chemical Society
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    • v.12 no.3
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    • pp.114-120
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    • 1968
  • Fe-EDTA complex, which is easily formed when Fe salt and EDTA.2Na are mixed in the aqueous medium, is found to be a very effective catalyst in the dehydropolycondensation of aminophenols. In the dehydropolycondensation of aminophenols, the catalyst, Fe(Ⅲ)-EDTA complex (higher oxidation state) is reduced to less stable Fe(Ⅱ)-EDTA complex (lower oxidation state), and the latter is easily oxidized by air to the original higher oxidation state complex, therefore the catalytic action of Fe-EDTA complex is found to be recycled effectively. Under the catalytic action of the above mentioned complex, p-aminophenol is polymerized in the aqueous medium to form the oligomers of p-aminophenol, which the degree of polymerization to be 5 or more. The oligomers formed contain partly quinone nucleus as well as amino and hydroxyl groups. In this study, the effects of the solvents and characteristics of the oligomers are discussed. These types of polymerizations catalyzed by the metallic chelate compounds are considered to be very closely related to the reactions in the living matters.

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New Route to N-Formylation of Primary Amines with Amino Acids as a Source of CO Using Polyaniline Catalyst

  • Ahn, Jeong-Soo;Chi, Ki-Whan;Hwang, Ho-Yun;Ryu, Kwang-Sun;Lee, Chan-Woo
    • Bulletin of the Korean Chemical Society
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    • v.30 no.10
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    • pp.2377-2380
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    • 2009
  • The treatment of primary amines with amino acids as a CO source in the presence of polyaniline emeraldine salts bring about N-formylation to give the corresponding formamides. This route to N-formylation methodology of primary amine represents the first reported example of a CO-transfer via radical mechanism by highly nanoporous polyaniline emeraldine salts catalyst.

Synthesis of New Bimetallic Chiral Salen Catalyst Bearing Co(BF4)2 Salt and Its Application in Asymmetric Ring Opening of Epoxide

  • Kim, Yong-Suk;Lee, Choong-Young;Kim, Geon-Joong
    • Bulletin of the Korean Chemical Society
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    • v.31 no.10
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    • pp.2973-2979
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    • 2010
  • The newly synthesized homogeneous chiral Co(III) salen complexes were anchored non-covalently on the acidic sites of mesoporous Al-SBA-15. The Bronsted and Lewis acidic sites are attributed to the immobilization of fluorine functionalized chiral salen complexes on the supports. XRD, BET, TEM, FT-IR and ESCA (XPS) analyses were performed to characterize the property of support, and the structure of new homogeneous and heterogeneous chiral Co salen catalyst. The homogeneous and heterogeneous catalysts could be applied in asymmetric ring opening of epichlorohydrine (ECH) by water. They showed very high enantioselectivity and a good yield up to 99% in the catalytic synthesis of optically active products.

Development of cobalt encased in nitrogen and sulfur co-doped carbon nanotube for non-precious metal catalyst toward oxygen reduction reaction

  • Kim, Tae-Hyun;Sang, Byoung-In;Yi, Sung-Chul
    • Journal of Ceramic Processing Research
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    • v.19 no.6
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    • pp.499-503
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    • 2018
  • In this paper, cobalt embedded in nitrogen and sulfur co-doped carbon nanotubes (CoNSTs) were synthesized for oxygen reduction reaction (ORR) catalysts. The CoNSTs were prepared through a facile heat treatment method without any templates. Different amounts of the metal salt were employed to examine the physicochemical and electrochemical properties of the CoNSTs. The CoNSTs showed the bamboo-like tube morphology with the encased Co nanoparticles in the tubes. Through the x-ray photoelectron spectroscopy analysis, the catalysts exhibited different chemical states of the nitrogen and sulfur species. As a result, the CoNST performed high activity toward the ORR in an acidic condition with the onset potential of 0.863 V (vs. reversible hydrogen electrode). It was clearly demonstrated from the electrochemical characterizations that the quality of the nitrogen and sulfur species significantly influences the ORR activity rather than the total amount of the dopants.

The development of PEMFC cathode using polyol method with directly grown CNT on carbon paper (Carbon paper에 직접적으로 생산한 CNT를 polyol 방법으로 Pt deposition하여 PEMFC cathode 개발)

  • Ok, Jinhee;Altalsukh, Dorjgotov;Rhee, Junki;Park, Sangsun;Shul, Yonggun
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.11a
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    • pp.84.1-84.1
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    • 2010
  • Since the discovery of the carbon nanotube(CNTs), they have attracted much attention because of unique properties that may impact many fields of science and technology. The considerable properties of CNTs include high surface area, outstanding thermal, electrical conductivity and mechanical stability. However, uniform deposition of Pt nanoparticles on carbon surface remains inaccessible territory because of the inert carbon surface. In this study, we prepared directly oriented CNTs on carbon paper as a catalyst support in cathode electrode. carbon surface was functionalized using aryl diazonium salt for increasing adhesion of Ni particles which is precursor for growing CNTs. For fabricate electrode, CNTs on carbon paper were grown by chemical vapor deposition using Ni catalyst and Pt nanoparticles were deposited on CNTs oriented carbon paper by polyol method. The performance was measured using Proton electrolyte Membrane Fuel Cell(PEMFC). The structure and morphology of the Pt nanoparticles on CNTs were characterized by Scanning electron Microscopy(SEM) and Transmission electron Microscopy (TEM). The average diameter of Pt nanoparticles was 3nm.

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Mechanism of Lipid Peroxidation in Meat and Meat Products -A Review

  • Min, B.;Ahn, D.U.
    • Food Science and Biotechnology
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    • v.14 no.1
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    • pp.152-163
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    • 2005
  • Lipid peroxidation is a primary cause of quality deterioration in meat and meat products. Free radical chain reaction is the mechanism of lipid peroxidation and reactive oxygen species (ROS) such as hydroxyl radical and hydroperoxyl radical are the major initiators of the chain reaction. Lipid peroxyl radical and alkoxyl radical formed from the initial reactions are also capable of abstracting a hydrogen atom from lipid molecules to initiate the chain reaction and propagating the chain reaction. Much attention has been paid to the role of iron as a primary catalyst of lipid peroxidation. Especially, heme proteins such as myoglobin and hemoglobin and "free" iron have been regarded as major catalysts for initiation, and iron-oxygen complexes (ferryl and perferryl radical) are even considered as initiators of lipid peroxidation in meat and meat products. Yet, which iron type and how iron is involved in lipid peroxidation in meat are still debatable. This review is focused on the potential roles of ROS and iron as primary initiators and a major catalyst, respectively, on the development of lipid peroxidation in meat and meat products. Effects of various other factors such as meat species, muscle type, fat content, oxygen availability, cooking, storage temperature, the presence of salt that affect lipid peroxidation in meat and meat products are also discussed.