• Title/Summary/Keyword: catalyst support

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Effects of Y-Zeolite as a Support on CO, $CC_3H_6$ Oxidation for Diesel Emission Control (디젤엔진 배출가스 저감을 위한 CO, $C_3H_6$의 산화반응에서 Y-제올라이트 담체의 영향)

  • 김문찬
    • Journal of Korean Society for Atmospheric Environment
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    • v.13 no.1
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    • pp.91-98
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    • 1997
  • Y-zeolite and ${\gamma}$-Al$_2$O$_3$ were used as supports on CO and $C_3$H$_{6}$ oxidation for diesel emission control. The catalysts composed of Pd and Pt as active components were wash coated on honeycomb type ceramic substrate. The oxidation of CO and $C_3$H$_{6}$ was carried out over prepared honeycomb in a fixed bed continuous reactor in the temperature range of 20$0^{\circ}C$~50$0^{\circ}C$ and 20,000 GHSV (h$^{-1}$ ). Surface area of Y-zeolite was larger than that of ${\gamma}$-Al$_2$O$_3$ due to channel structure of Y-zeolite. Therefore, high conversion of CO and $C_3$H$_{6}$ could be obtained because of good dispersion of active metals over Y-zeolite. The honeycomb used Y-zeolite as a support showed higher $C_3$H$_{6}$ conversion than that of ${\gamma}$-Al$_2$O$_3$ due to better cracking and isomerization activity of Y-zeolite. PdPt catalyst showed high conversion of CO and $C_3$H$_{6}$ at low temperature region, 20$0^{\circ}C$~30$0^{\circ}C$, for their synergy effects. PdPt/Y-Zeolite catalyst could achieve more than 80% conversion of $C_3$H$_{6}$ at 30$0^{\circ}C$. The use of Y-zeolite as a support increased CO and $C_3$H$_{6}$ conversion, and decreased SO$_2$ conversion very effectively. Y-zeolite found to have a good adaptability as a support for the diesel emission after treatment system.

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Fabrication of hyaluronic acid membrane using electrospinning method and its application as a catalyst support for gold nanoparticles (전기방사를 이용한 히알루론산 멤브레인의 제조 및 금 나노입자 촉매 담체로의 응용)

  • Lee, Namhun;Park, Hyun-Min;Lee, Sang-Myung;Lee, Dae-Won
    • Journal of Industrial Technology
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    • v.38 no.1
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    • pp.15-19
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    • 2018
  • In this study, hyaluronic acid (HA) was electro-spun to fabricate nanofibrous membranes for support materials. Because HA is very hygroscopic, it is difficult to obtain enough viscosity to apply electrospinning method. Therefore, we mixed HA with polyethylene oxide (PEO) to obtain proper viscosity and added adipic acid (ADH) to promote cross-linking of PEO/HA during electrospinning. The morphology of PEO/HA membrane was optimized according to PEO/HA concentration ratio and spinning rate. Finally, we fabricated gold-nanoparticle-embedded PEO/HA membranes and their catalyst activities were evaluated in tetramethylbenzidine (TMB) oxidation.

Activity of $V_2O_5/TiO_2$Catalyst Using Domestic Pigment Titania as Support for Nitric Oxide Reducton (국내 안료용 타이타니아를 담체로 이용한 $V_2O_5/TiO_2$ 촉매상에서 질소산화물 제거활성)

  • 이정빈;이인영;김동화;엄희문;지평삼;추수태;남인식
    • Journal of Korean Society for Atmospheric Environment
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    • v.15 no.6
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    • pp.791-797
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    • 1999
  • The activity of domestic pigment titania$(TiO_2)$ impregnated with vanadia$(V_2O_5)$ was investigated in the laboratory microreactor. The meta-titanic acid$(TiO(OH)_2)$ which was produced at Hankook Titanium was selected as the precursor for support. The domestic pigment $TiO_2$ showed higher activity in the reduction of NO with $NH_3$ than the foreign commercial $TiO_2$. $WO_3$ were added to domestic $V_2O_5/TiO_2$ catalytic system to improve the catalytic activity at higher reaction temperature between 400~50$0^{\circ}C$ Also, the deactivation of domestic $V_2O_5/TiO_2$ and $WO_3-V_2O_5/TiO_2$ catalyst by $SO_2$ and $H_2O$ was investigated.

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High Electrochemical Activity of Pt-Cu Alloy Support on Carbon for Oxygen Reduction Reaction (산소 환원 반응을 위한 탄소기반 Pt-Cu 합금의 높은 전기적 촉매 활성)

  • KIM, HAN SEUL;RYU, SU CHAK;LEE, YOUNG WOOK;SHIN, TAE HO
    • Journal of Hydrogen and New Energy
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    • v.30 no.6
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    • pp.549-555
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    • 2019
  • Electrocatalysis of oxygen reduction reaction (ORR) using Pt nanoparticles or bimetal on carabon was studied. Currently, the best catalyst is platinum, which is a limited resource and expensive to commercialize. In this paper, we investigated the cheaper and more active electrocatalysts by making Pt nanoparticles and adding 3D transition metal such as copper. Electrocatalysts were obtained by chemical reduction based on ethylene glycol solutions. Elemental analysis and particle size were confirmed by XRD and TEM. The electrochemical surface area (ECSA) and activity of the catalyst were determined by electrochemical techniques such as cyclic voltammetry and linear sweep voltammetry method. The commercialized Pt support on carbon (Pt/C, JM), synthesis Pt/C and synthesis Pt3Cu1 alloy nanoparticles supported on carbon were compared. We confirmed that the synthesized Pt3-Cu1/C has high electrochemical performance than commercial Pt/C. It is expected to develop an electrocatalyst with high activity at low price by increasing the oxygen reduction reaction rate of the fuel cell.

Study of US/EU National Innovation Policies Based on Nanotechnology Development, and Implications for Korea

  • Lim, Jung Sun;Shin, Kwang Min;Yoon, Jin Seon;Bae, Seoung Hun
    • Journal of Information Science Theory and Practice
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    • v.3 no.1
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    • pp.50-65
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    • 2015
  • Recently US/EU governments are utilizing nanotechnology as a key catalyst to support national innovation policies with economic recovery goals. US/EU nano policies have been serving as a global model to various countries, including Korea. So the authors initially seek to understand US/EU national innovation policy interconnections, and then find the role of nanotechnology development within. To strengthen national policy coherence, nanotechnology development strategies are under evolution as an innovation catalyst for promoting commercialization. To strategically support nano commercialization, EHS (Environmental, Health, Safety) and informatics are invested as priority fields to strengthen social acceptance and sustainability of nano enabled products. The current study explores US/EU national innovation policies including nano commercialization, EHS, and Informatics. Then obtained results are utilized to analyze weaknesses of Korean innovation systems of connecting creative economy and nanotechnology development policies. Then ongoing improvements are summarized focusing on EHS and informatics, which are currently prominent issues in international nanotechnology development.

A Study on Reaction Characteristics of $CO_2$ Conversion Methanation over Pt Catalysts for Reduction of GHG (온실가스 저감을 위한 Pt계 촉매상 $CO_2$ Methanation 전환반응 특성에 관한 연구)

  • Hong, Sung Chang
    • Applied Chemistry for Engineering
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    • v.23 no.6
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    • pp.572-576
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    • 2012
  • This study presents the $CO_2$ methanation reaction on Pt catalysts for reducing the amount of $CO_2$, one of greenhouse gases. The AlO(OH) of $Al_2O_3$precusor was used as a support via a thermal treatment and the Pt was used as an active metal. In XRD results, it was confirmed that the Pt was well dispersed and the support existed as the gamma $Al_2O_3$phase. The $Pt/Al_2O_3$ catalyst calcined at $600^{\circ}C$ showed the highest conversion efficiency and selectivity.

Effect of Support on Synthesis Gas Production of Supported Ni Catalysts (니켈 담지촉매를 이용한 합성가스 제조 시 담체의 영향)

  • Kim, Sang-Bum;Park, Eun-Seok;Cheon, Han-Jin;Kim, Young-Kook;Lim, Yun-Soo;Park, Hong-Soo;Hahm, Hyun-Sik
    • Journal of the Korean Applied Science and Technology
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    • v.20 no.4
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    • pp.289-295
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    • 2003
  • Synthesis gas is produced commercially by a steam reforming process. However, the process is highly endothermic and energy intensive. Thus, this study was conducted to produce synthesis gas by the partial oxidation of methane to cut down the energy cost. Supported Ni catalysts were prepared by the impregnation method. To examine the activity of the catalysts, a differential fixed bed reactor was used, and the reaction was carried out at $750{\sim}850^{\circ}C$ and 1 atm. The fresh and used catalysts were characterized by XRD, XPS, TGA and AAS. The highest catalytic activity was obtained with the 13wt% Ni/MgO catalyst, with which methane conversion was 81%, and $H_2$ and CO selectivities were 94% and 93%, respectively. 13wt% Ni/MgO catalyst showed the best $MgNiO_2$ solid solution state, which can explain the highest catalytic activity of the 13wt% Ni/MgO catalyst.

Performance Evaluation of Ethanol Blended Hydrogen Peroxide Thrusters (에탄올 블렌딩한 과산화수소 추력기의 성능평가)

  • Lee, Jeong-Sub;Kwon, Se-Jin
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2012.05a
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    • pp.100-103
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    • 2012
  • The blending method that is an addition of small quantity of fuel was used to increase the performance of green propellant thruster. 90 wt.% hydrogen peroxide as a green propellant was selected, and ethanol was used as a blended fuel. The o/f ratio was chosen as 50 which has higher theoretical performance than 98 wt.% hydrogen peroxide. The chamber temperature of blended hydrogen peroxide was higher than adiabatic chamber temperature of hydrogen peroxide. Therefore, performance can be improved by ethanol blending. Several catalyst and its support were compared to find appropriate catalyst for decomposition and combustion of ethanol blended hydrogen peroxide. As a experimental results, Pt was suitable, but $MnO_2$ had a chamber instability when it was reused. The ${\alpha}-Al_2O_3$ which is high heat-resistant support showed very unstable performance in both Pt and $MnO_2$ catalyst since it has low decomposition performance.

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Effect of an Al underlayer on the Growth of mm-long Thin Multi-walled Carbon Nanotubes in Water-Assisted Thermal CVD

  • Choi, In-Sung;Jeon, Hong-Jun;Lee, Han-Sung;Lee, Nae-Sung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.26-26
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    • 2009
  • Vertically aligned arrays of mm-long multi-walled carbon nanotubes (MWCNTs) on Si substrates have been synthesized by water-assisted thermal chemical vapor deposition (CVD). The growth of CNTs was investigated by changing the experimental parameters such as growth temperature, growth time, gas composition, annealing time, catalyst thickness, and Al underlayer thickness. The 0.5-nm-thick Fe served as catalyst, underneath which Al was coated as a catalyst support as well as a diffusion barrier on the Si substrate. We grew CNTs by adding a little amount of water vapor to enhance the activity and the lifetime of the catalyst. Al was very good at producing the nm-size catalyst particles by preventing "Ostwald ripening". The Al underlayer was varied over the range of 15~40 nm in thickness. The optimum conditions for the synthesis parameters were as follows: pressure of 95 torr, growth temperature of $815^{\circ}C$, growth for 30 min, 60 sccm Ar + 60 sccm $H_2$ + 20 sccm $C_2H_2$. The water vapor also had a great effect on the growth of CNTs. CNTs grew 5.03 mm long for 30 min with the water vapor added while CNTs were 1.73 mm long without water vapor at the same condition. As-grown CNTs were characterized by using scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), and Raman spectroscopy. High-resolution transmission electron microscopy showed that the as-grown CNTs were of ~3 graphitic walls and ~6.6 nm in diameter.

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