• 제목/요약/키워드: Cu-catalyst

검색결과 356건 처리시간 0.029초

Synthesis of Polymers Including Both Triazole and Tetrazole by Click Reaction

  • Shin, Jung-Ah;Lim, Yeong-Gweon;Lee, Kyung-Hee
    • Bulletin of the Korean Chemical Society
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    • 제32권2호
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    • pp.547-552
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    • 2011
  • Azido contained polymers were treated with various substituted N-propargyl tetrazoles in $CH_2Cl_2/H_2O$ at room temperature by Cu-catalyzed [2+3] cycloaddition to afford high yields of the corresponding polymers, possessing both triazole and tetrazole moiety.

알칼리 $NaBH_4$ 용액의 수소발생특성에 미치는 Co-P 촉매의 영향 (Effects of Co-P Catalysts on Hydrogen Generation Properties from Alkaline $NaBH_4$ Solution)

  • 조근우;권혁상
    • 한국수소및신에너지학회논문집
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    • 제16권4호
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    • pp.379-385
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    • 2005
  • Effects of Co and Co-P catalysts on the hydrolysis of alkaline $NaBH_4$ solution were investigated. Co and Co-P catalysts were prepared on Cu substrate by electroplating. Hydrogen generation rate of Co-P catalyst was much faster than that of Co catalyst, demonstrating that Co-P had higher intrinsic catalytic activity for the hydrolysis of $NaBH_4$ than Co. Hydrogen generation properties of Co-P catalysts largely depended on cathodic current density and electroplating time because they influenced on the P concentration of the Co-P catalysts. Maximum hydrogen generation rate of Co-P catalyst was 1066 ml/min.g-catalyst in 1 wt.% NaOH + 10 wt.% $NaBH_4$ solution at $20^{\circ}C$, which was obtained at cathodic current density of $0.01\;A/cm^2$ for 130 s.

금속이온교환된 Mg/Cu-ZSM-5 촉매를 사용한 배연 탈질 공정에서 De-NOx활성 비교연구 (A Comparative Study on the NOx Removal Activities of Metal-ion-exchanged Mg/Cu-ZSM-5 Catalysts in the Treatment of Flue Gas from Stationary Sources)

  • 김재천;이병용;정석진
    • 한국대기환경학회지
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    • 제12권4호
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    • pp.421-428
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    • 1996
  • In this study, in order to make up its draw-back in Cu-ZSM-5 catalytic system, some of transition metals or alkaline earth metals were cocation-exchanged in Cu-ZSM-5. Among various cocation-ion-exchanged ZSM-5 catalysts, Mg/Cu-ZSM-5 has been found the most active and durable in NOx reduction even at high oxygen content as well as at the presence of water vapor. The role of Mg in ZSM-5 is supposed to prevent the dealumination of aluminum ions in super-cage even at harsh hydro-thermal conditions, and also it seems to stabilize the Cu ions in the structure. In order to prepare commercially available catalysts, Mg/Cu-ZSM-5 catalysts were wash-coated on the surface of honeycomb type monolith, and tested in terms of catalytic activities. As a result, it was found that the catalyst prepared bt the wash-coating showed satisfactorily high NOx conversion for the practical use in SCR process.

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The $CO_{2}$ Hydrogenation toward the Mixture of Methanol and Dimethyl Ether: Investigation of Hybrid Catalysts

  • 준기원;K.S. Rama Rao;정미희;이규완
    • Bulletin of the Korean Chemical Society
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    • 제19권4호
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    • pp.466-470
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    • 1998
  • Catalytic hydrogenation of carbon dioxide for the simultaneous synthesis of methanol and dimethyl ether (together called oxygenates) over a combination of methanol synthesis and methanol dehydration catalysts has been studied. Various methanol synthesis and methanol dehydration catalysts were examined for this reaction. The addition of promotors like $Ga_2O_3\; and\; Cr_2O_3$ to Cu/ZnO catalyst gave much more enhanced yield on the formation of oxygenates. From the results, the promotional effect of $Cr_2O_3$ has been explained in terms of increase in the intrinsic activity of Cu while that of $Ga_2O_3$ being increase in the dispersion of Cu. Among the methanol dehydration catalysts examined, the solid acids bearing high population of intermediate-strength acid sites were found to be very effective for the production of oxygenates. HY zeolite which contains strong acid sites produce small amount of hydrocarbons as by-products. However, CuNaY zeolite in which the presence of strong acid sites are minimum gives very high oxygenates yield without the formation of hydrocarbons.

12wt% Co 담지 FT 촉매 제조시 유기용매가 촉매활성에 미치는 영향연구 (The Effect of Organic Solvents on the Activity for the Synthesis of 12wt% Co-based FT Catalyst)

  • 이지윤;한자령;정종태;백영순
    • 한국수소및신에너지학회논문집
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    • 제26권4호
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    • pp.339-346
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    • 2015
  • The synthesis of Fischer-Tropsch (FT) oil is the catalytic hydrogenation of CO to give a range of products, which can be used for the production of high-quality diesel fuel, gasoline and linear chemicals. This studied catalyst was prepared Cobalt-supported alumina and silica by the incipient wet impregnation of the nitrates of cobalt, promoter and organic solvent with supports. Cobalt catalysts were calcined at $350^{\circ}C$ before being loaded into the FT reactors. After the reduction of catalyst has been carried out under $450^{\circ}C$ for 24h, FT reaction of the catalyst has been carried out at GHSV of 4,000/hr under $200^{\circ}C$ and 20atm. From these experimental results, we have obtained the results as following; In case of $SiO_2$ catalysts, the activity of 12wt% $Cobalt-SiO_2$ synthesized by organic solvent was about 2 or 3 times higher than the activity of 12wt% $Cobalt-SiO_2$ catalyst synthesized without organic solvent. In particular, the activity of the $Cobalt-SiO_2$ catalyst prepared in the presence of an organic solvent P was two to three times higher than that of the $Cobalt-SiO_2$ catalyst prepared without the organic solvent. Effect of Cr and Cu metal as a promoter was found little. 200 h long-term activity test was performed with a $Co/SiO_2$ catalyst prepared in the presence of an organic solvent of Glyoxal solution.

Tin-Free Three-Component Coupling Reaction of Aryl Halides, Norbornadiene (or Norbornene), and Alkynols Using a Palladium Catalyst

  • Choi, Cheol-Kyu;Hong, Jin-Who;Tomita, Ikuyoshi;Endo, Takeshi
    • Bulletin of the Korean Chemical Society
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    • 제23권1호
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    • pp.112-118
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    • 2002
  • Good-to-excellent yields of 2,3-Disubstituted norbornenes (or norbornanes) were obtained using a Pd/Cu catalyzed three-component ternary coupling reaction of aryl halides, norbornadiene (or norbornene), and alkynols in toluene at $100{\circ}C$ in the presence of 5.5 M NaOH as a base and benzyltriethylammonium chloride as a phase transfer catalyst. The results of experiments using various aromatic halides suggest that the ternary coupling reaction is promoted by bromide.

Development of Click Chemistry in Polymerization and Applications of Click Polymer

  • Karim, Md. Anwarul
    • 고무기술
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    • 제13권1호
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    • pp.1-9
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    • 2012
  • Click chemistry had enjoyed a wealthy decade after it was introduced by K.B.Sharpless and his co-worker on 2001. Since there is no optimized method for synthesis of click polymer, therefore, this paper introduced three click reaction methods such as catalyst, non-catalyst and azide-end capping for fluorene-based functional click polymers. The obtained polymers have reasonable molecular weight with narrow PDI. The polymers are thermally stable and almost emitted blue light emission. The synthesized fluorene-based functional click polymers were characterized to compare the effect of click reaction methods on polymer electro-optical properties as well as device performance on quasi-solid-state dye sensitized solar cells (DSSCs) applications. The DSSCs with configuration of $SnO_2:F/TiO_2/N719$ dye/quasi-solid-state electrolyte/Pt devices were fabricated using these click polymers as a solid-state electrolyte components. Among the devices, the catalyzed click polymer composed device exhibited a high power conversion efficiency of 4.62% under AM 1.5G illumination ($100mW/cm^2$).These click polymers are promising materials in device application and $Cu^I$-catalyst 1, 3-dipolar cycloaddition click reaction is an efficient synthetic methodology.

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Carbon bead-supported copper-dispersed carbon nanofibers: An efficient catalyst for wet air oxidation of industrial wastewater in a recycle flow reactor

  • Yadav, Ashish;Verma, Nishith
    • Journal of Industrial and Engineering Chemistry
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    • 제67권
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    • pp.448-460
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    • 2018
  • Copper nanoparticle-doped and graphitic carbon nanofibers-covered porous carbon beads were used as an efficient catalyst for treating synthetic phenolic water by catalytic wet air oxidation (CWAO) in a packed bed reactor over 10-30 bar and $180-230^{\circ}C$, with air and water flowing co-currently. A mathematical model based on reaction kinetics assuming degradation in both heterogeneous and homogeneous phases was developed to predict reduction in chemical oxygen demand (COD) under a continuous operation with recycle. The catalyst and process also showed complete COD reduction (>99%) without leaching of Cu against a high COD (~120,000 mg/L) containing industrial wastewater.

금속이온이 치환된 Y형 제올라이트에서 벤젠의 촉매연소반응 (Catalytic Combustion of Benzene over Metal Ion-Substituted Y-Type Zeolites)

  • 홍성수
    • 청정기술
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    • 제22권3호
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    • pp.161-167
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    • 2016
  • 여러 가지 금속이온이 치환된 제올라이트에서 벤젠의 촉매연소 반응에 대해 연구하였다. 사용한 제올라이트 중 Y(4.8)형 제올라이트가 가장 높은 활성을 보여주었고, Y(4.8)형 제올라이트에 치환된 금속 이온 중 구리이온이 가장 높은 활성을 보여주었다. 촉매의 활성은 산소 TPD에 의해 얻어진 흡착산소의 양에 비례하였다. Cu/Y(4.8) 촉매에서 Cu 이온의 농도가 커질수록 반응활성이 증가하였다. 벤젠의 연소반응의 전환율은 반응물 중 벤젠의 농도보다는 산소 농도의 영향을 많이 받았다. 또한, 반응물에 첨가된 물은 촉매 활성을 감소시켰다.

Effect of KHCO3 Concentration Using CuO Nanowire for Electrochemical CO2 Reduction Reaction

  • Kanase, Rohini Subhash;Kang, Soon Hyung
    • 마이크로전자및패키징학회지
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    • 제27권4호
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    • pp.11-17
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    • 2020
  • Copper has been proved to be the best catalyst for electrochemical CO2 reduction reaction, however, for optimal efficiency and selectivity, its performance requires improvements. Electrochemical CO2 reduction reaction (RR) using CuO nanowire electrode was performed with different concentrations of KHCO3 electrolyte (0.1 M, 0.5 M, and 1 M). Cu(OH)2 was formed on Cu foil, followed by thermal-treatment at 200℃ under the air atmosphere for 2 hrs to transform it to the crystalline phase of CuO. We evaluated the effects of different KHCO3 electrolyte concentrations on electrochemical CO2 reduction reaction (RR) using the CuO nanowire electrode. At a constant current (5mA), low concentrated bicarbonate exhibited a more negative potential -0.77 V vs. Reversible Hydrogen Electrode (RHE) (briefly abbreviated as VRHE), while the negative potential reduced to -0.33 VRHE in the high concentration of bicarbonate solution. Production of H2 and CH4 increased with an increased concentration of electrolyte (KHCO3). CH4 production efficiency was high at low negative potential whereas HCOOH was not influenced by bicarbonate concentration. Our study provides insights into efficient, economically viable, and sustainable methods of mitigating the harmful environmental effects of CO2 emission.