• Title/Summary/Keyword: Ni Catalyst

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Fabrication and H2S Sensing Property of Nickel Oxide and Nickel Oxide-Carbon Nanotube Composite (산화니켈 및 탄소나노튜브/산화니켈 복합체 가스센서의 제작과 황화수소 감지 특성)

  • Yang, Haneul;Chinh, Ngyuen Duc;Hieu, Ngyuen Minh;Park, Jihwan;Hong, Soonhyun;yun, Hongkwan;Kim, Chunjoong;Kim, Dojin
    • Korean Journal of Materials Research
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    • v.28 no.8
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    • pp.466-473
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    • 2018
  • Nickel oxide(NiO) thin films, nanorods, and carbon nanotube(CNT)/NiO core-shell nanorod structures are fabricated by sputtering Nickel at different deposition time on alumina substrates or single wall carbon nanotube templates followed by oxidation treatments at different temperatures, 400 and 700C. Structural analyses are carried out by scanning electron microscopy and x-ray diffraction. NiO thinfilm, nanorod and CNT/NiO core-shell nanorod structurals of the gas sensor structures are tested for detection of H2S gas. The NiO structures exhibit the highest response at 200C and high selectivity to H2S among other gases of NO, NH3, H2, CO, etc. The nanorod structures have a higher sensing performance than the thin films and carbon nanotube/NiO core-shell structures. The gold catalyst deposited on NiO nanorods further improve the sensing performance, particularly the recovery kinetics.

Autothermal Reforming Reaction of Methane using Ni-Ru/Al2O3-MgO Metallic Monolith Catalysts (Ni-Ru/Al2O3-MgO 금속 모노리스 촉매체를 이용한 메탄의 자열 개질반응)

  • Lee, Chang-Ho;Lee, Tae-Jun;Shin, Jang-Sik;Lee, Jong-Dae
    • Journal of the Korean Applied Science and Technology
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    • v.28 no.3
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    • pp.321-328
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    • 2011
  • The autothermal reforming reaction of methane was investigated to produce hyd rogen with Ni/CeO2ZrO2, Ni/Al2O3-MgO and Ni-Ru/Al2O3-MgO catalysts. Honeycomb metalli c monolith was applied in order to obtain high catalytic activity and stability in autothermal r eforming. The catalysts were characterized by XRD, BET and SEM. The influence of various catalysts on hydrogen production was studied for the feed ratio(O2/CH4, H2O/CH4). The O2/CH4 and H2O/CH4 ratio governed the methane conversion and temperature profile of reactor. Th e reactor temperature increased as the reaction shifted from endothermic to exothermic reactio n with increasing O2/CH4 ratio. Among the catalysts used in the experiment, the Ni-Ru/Al2O3-MgO catalyst showed the highest activity. The 60% of CH4 conversion was obtained, and th e reactor temperature was maintained 600C at the condition of GHSV=10000h1 and feed ratio S/C/O=0.5/1/0.5.

Nickel Complexes Having (N-C-N) Tridentate Ligands ((N-C-N) 세자리 리간드를 가지는 니켈 착물)

  • Lee, Dong-Hwan;Park, Soon-Heum
    • Journal of the Korean Chemical Society
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    • v.51 no.6
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    • pp.499-505
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    • 2007
  • Monomeric complexes of nickel(II) having terdentate bis(imino)aryl ligands (N,C,N-pincer) are reported. New complexes (2,6-(ArN=CH)2C6H3)NiBr (Ar=2,6-dimethylphenyl (1), 2,6-diisopropylphenyl (2)) have been synthesized through oxidative addition of 1,3-(ArN=CH)2C6H3Br (bis(N-Ar)-2-bromoisophthalaldimine: Ar=Ph-2,6-Me2, Ph-2,6-iPr2) to Ni(COD)2 (COD=1,5-cyclooctadiene), in high yields. The development of a synthetic route to ligands and nickel complexes is outlined. The complexes were characterized by IR, 1H-NMR and elemental analysis. Full characterization of complexes 1 and 2 is discussed. An investigation into the catalytic activity of the complexes in ethylene polymerization was performed, resulting in no formation of polyethylenes but producing a small amount of oily oligomers. Preliminary results indicate that the pincer complexes were found to be inactive as catalysts in ethylene polymerization.

Decomposition Study of Acetaldehyde by Metal-oxide Catalysts (금속산화물 촉매에 의한 CH3CHO의 분해반응 연구)

  • Lee, Chang-Seop;Kim, Young-Eun;Choi, Sung-Woo
    • Journal of the Korean Institute of Gas
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    • v.11 no.2 s.35
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    • pp.25-30
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    • 2007
  • The catalysts for decomposition reaction of acetaldehyde were investigated. The catalysts were prepared with transition metal Ni, Mo, Al on γAl2O3 support by impregnation method. Physio-chemical properties of catalysts were characterized by SEM-EDS, XRD, XPS, BET and TPR techniques. The conversion efficiency of catalysts for acetaldehyde was measured in the temperature range of 150500C by GC through the micro reactor system. The 8 wt% Ni/γAl2O3 was found to be the most active catalyst of mono-metal catalysts tested, and the 1-3 wt% NiAl/γAl2O3 showed higher conversion efficiency than other bimetallic catalysts.

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Facile Fabrication of Bimetallic Catalysts via Selective N atoms of N-Doped Carbon Nanotubes and Their Superior Catalytic Activities for Hydrogen Generation (질소가 포함된 탄소나노튜브의 질소 원자를 이용한 이중 금속 촉매 제조 및 그의 수소 발생 촉매 특성 분석)

  • Shin, Weon Ho;Jeong, Hyung Mo;Choi, Yoon Jeong;Kang, Jeung Ku
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.11a
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    • pp.111.2-111.2
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    • 2010
  • One-dimensional nanostructures such as carbon nanotubes could be ideal templates for formation of metallic nanoparticles. Furthermore, bimetallic component nanoparticles have recently been interesting issues for having high catalytic activity. This work provides both a facile method to synthesize bimetallic catalysts via N atoms of carbon nanotubes and also a picture about how to design the optimal bimetallic catalyst for hydrogen generation from the hydrogen storage material. In principle, the ratio of one component to another component could be generically extended to fabricate the high-performance bimetallic catalysts on host nanostructures. Indeed, we demonstrate that the bimetallic catalyst composed of the optimum composition results in the excellent hydrogen generation property from an aqueous borane ammonia solution, thus being capable of satisfying the Depart of Energy in USA target required for many advanced applications even with the small amount of our bimetallic catalysts attached onto the N-doped carbon nanotubes. This high hydrogen generation rate is found to be attributed to the optimal distance between active Pt and cheap Ni atoms for effective hydrogen generation.

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Etching Treatment of Vertically Aligned Carbon Nanotubes for the Application to Biosensor (바이오센서로의 응용을 위한 수직 배열된 탄소나노튜브의 식각처리)

  • Choi, Eun-Chang;Park, Yong-Seob;Choi, Won-Seok;Hong, Byung-You
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.7
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    • pp.594-598
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    • 2008
  • The metal catalyst particles which there is as impurities on a tip part of carbon nanotube (CNT) are not good to apply it to a nano-electronic device. It was very important the opening of CNT-tip to fix a target bio material and a material to accept in CNT in a biosensor, so we performed HNO3 wet etching to remove the metal catalyst particle which there was on a tip part of CNT grown up in the study and observed the opened CNT-tip with etching time. We synthesized the CNTs using a HF-PECVD method and choses the CNT length of 700 nm for the application of nano-electronic device such as a biosensor etc.. We observed the opened CNT-tip with wet etching times of HNO3 (10, 30, 60 min). From the results, we observed that the CNT-tip was opened with the increase of wet etching time lively. In case of CNTs etched during 60 min, we confirmed that there was not the ratio of Ni included in CNTsI as catalyst. Conclusively, in the case of CNT etched for 60 minutes, it is completely good for application of a biosensor and, in addition, the metal-free CNTs will contribute to the application of other nanoelectronic devices.

Development of High Performance WGS Catalyst for Fuel Processor Applications (연료 개질기용 고성능 수성가스 전환반응 촉매 개발)

  • Lee, Yoon-Ju;Ryu, Jong-Woo;Kim, Dae-Hyun;Choi, Eun-Hyung;Noh, Won-Suck;Lee, Sang-Deuk;Moon, Dong-Ju
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.11a
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    • pp.451-454
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    • 2006
  • WGS reaction over Mo2C and ceria based catalysts was investigated to develop an alternative commercial Cu-Zn/Al2O3 catalyst for fuel processor and hydrogen station. The Mo2C catalysts were prepared by a temperature programmed method and the various metal supported cerium oxide catalysts were prepared by an Impregnation method. The catalysts were characterized by the N2 physisorption, Co chemisorption, XRD, TEM and TPR. It was found that Mo2C and 0.2wt% Pt-40wt%, Ni/CeO2 catalysts had higher activity and stability than the Cu-Zn/Al203 above 260C. Moreover, CO conversion of more than 85% was observed at 280300C. But all catalysts were deactivated during the thermal cycling runs. The results suggest that these catalysts are an attractive candidate for the alternative Cu-Zn/Al2O3 catalyst for fuel processor and hydrogen station applications.

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A Study on the Design of MCFC Off-Gas Catalytic Combustor (MCFC Off-gas 촉매연소기 설계에 관한 연구)

  • Lee, Sang-Min;Lee, Young-Duk;Ahn, Kook-Young;Hong, Dong-Jin;Kim, Man-Young
    • Journal of Hydrogen and New Energy
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    • v.18 no.4
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    • pp.406-412
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    • 2007
  • An experimental study on the design of a catalytic combustor for 1.6 kW MCFC system has been performed. The roles of the catalytic combustor are to completely burn anode off-gas and to supply sufficient CO2 to cathode channels. In order to avoid hot spot or fuel slippage, flow uniformity at the catalyst inlet was achieved by installing two crossing perforated plates between the catalyst and the mixing chamber with minimal pressure drop. A Pd/Ce/Ni-Al2O3 catalyst was used for complete combustion of the off-gas at GHSV=36,000.

Nanocarbon synthesis using plant oil and differential responses to various parameters optimized using the Taguchi method

  • Tripathi, Suman;Sharon, Maheshwar;Maldar, N.N.;Shukla, Jayashri;Sharon, Madhuri
    • Carbon letters
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    • v.14 no.4
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    • pp.210-217
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    • 2013
  • The synthesis of carbon nanomaterials (CNMs) by a chemical vapor deposition method using three different plant oils as precursors is presented. Because there are four parameters involved in the synthesis of CNM (i.e., the precursor, reaction temperature of the furnace, catalysts, and the carrier gas), each having three variables, it was decided to use the Taguchi optimization method with the 'the larger the better' concept. The best parameter regarding the yield of carbon varied for each type of precursor oil. It was a temperature of 900C + Ni as a catalyst for neem oil; 700C + Co for karanja oil and 500C + Zn as a catalyst for castor oil. The morphology of the nanocarbon produced was also impacted by different parameters. Neem oil and castor oil produced carbon nanotube (CNT) at 900C; at lower temperatures, sphere-like structures developed. In contrast, karanja oil produced CNTs at all the assessed temperatures. X-ray diffraction and Raman diffraction analyses confirmed that the nanocarbon (both carbon nano beads and CNTs) produced were graphitic in nature.

Hydrocarbon Synthesis of Waste Lignocellulosics by Liquefaction Reaction of Thermochemical Deoxyhdrogenolysis Method (II) (목질폐재(木質廢材)의 열(熱)-화학적(化學的) 탈(脫)산소-수소첨가반응(환원반응)에 의한 액화(液化)탄화수소의 합성 (II))

  • Lee, Byung-Guen
    • Journal of the Korean Wood Science and Technology
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    • v.19 no.4
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    • pp.80-84
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    • 1991
  • Lignocellulosic biomass including acetosolv ricestraw and spruce lignin were liquefied and converted into liquid hydrocarbons by catalytic hydroliquefaction reaction. These experimental works were carried out in 1-liter-capacity autoclave using 50% tetralin and m-cresol solution respectively as soluble solvent and Ni. Pd. Fe and red mud as catalyst. H2 gas was supplied into the reactor for escaltion of deoxhydroenolysis reaction. Catalyst concentrations were 1 % of raw material based on weight. The ratio between raw materials and soluble solvent are 1g and 10cc. The reaction conditions are 400-700C of reaction temperature, 10-50 atms of reaction pressure. The highest yield of hydrocarbon, so called "product oil" showed 32% and 5.5% of lowest char formation when red mud was used as catalyst. The product oil yields from those of other catalysts were in the range of 20-29%. The influence of different initial hydrogen pressures was examined in the range d 30-50 atms. A minimum pressure of 35 atms was necessary to obtain a complete recovery of souble solvent for recycling.

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