• Korean Chemical Engineering Research
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• 제44권4호
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• pp.363-368
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• 2006

$C_9$-알데히드를 수소화하여 $C_9$-알콜을 제조하는 공정에 사용하기 위한 최적의 촉매를 선정하고, $C_9$-알콜의 수율을 극대화하기 위한 운전 조건을 확립하기 위한 실험을 수행하였다. 구리 전구체로 acetate를 사용하고 침전제로 $Na_2CO_3$를 사용하여 제조한 $CuO/ZnO/Al_2O_3$(60:30:10 wt％) 촉매의 표면적 및 구리 비표면적이 가장 우수하였으며 $C_9$-알데히드 수소화 반응에서도 가장 우수한 성능을 보였다. 최적화된 촉매를 장착한 trickle bed 반응기를 사용하여 $175^{\circ}C$, 800 psi, $WHSV=3hr^{-1}$의 조건에서 94.1 wt％의 $C_9$-알콜 수율을 얻었다. 알데히드의 수소화 반응에 사용되는 다른 촉매들과 비교한 결과 Ni/kieselghur 촉매와 유사한 성능을 보였으며 $Cu-Ni-Cr-Na/Al_2O_3$ 촉매 및 $Ni-Mo/Al_2O_3$ 촉매의 경우보다 우수한 성능을 보이는 것을 확인하였다. 장기 촉매 테스트를 통해서 촉매의 안정성을 확인한 결과 약 72시간 이후에는 고비점 부산물의 생성량 증가로 인하여 $C_9$-알콜의 수율이 약간씩 감소하였다.

• 한국대기환경학회지
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• 제6권1호
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• pp.57-72
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• 1990

The oxidation of carbon monoxide on a catalyst, $LaSrNiCoO_3$ was investigatigated with a plug flow system. Kinetic quantities such as reaction-rate, reaction order and Arhenius-parameters at various reactor temperature from 200$^\circ$C to 300$^\circ$C were determined. Also, the optimum condition for the oxidation of carbon monoxide with this catalyst was determined and are as follows. Partial pressure of oxigen ; 428mmHg Partial pressure of carbon monoxide ; 332mmHg Mixed moral ratio of oxigen and Carbon monoxide ; 1.3 : 1 Total gas flow ; 224ml/min Reaction temperature ; 340$^\circ$C The reaction kinetic equation at the optimum condition, temperature range from 200$^\circ$C to 340$^\circ$C, are as follow. $$ $v = Ae^{6.5Kcal/RT} [CO]^{0.93 \sim 0.98} [O_2]^{0.42 \sim 0.50}$ $$ In addition to this, numerical calculation were performed to evaluate the mass and heat transfer effect on this system.

• Korean Chemical Engineering Research
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• 제58권4호
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• pp.658-664
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• 2020

Zeolite HY is wet impregnated with Ni (0.1, 0.3, 0.4, 0.5 wt%), Pt (0.1 wt%) and reduced in presence of hydrogen to form nanosized particles of Ni and Pt. All the catalysts were characterized by XRD, TEM, ESCA, NH₃-TPD, Pyridine adsorbed FT-IR and BET. Characterization results confirm that the Ni and Pt fractions effectively rehabilitated the physio-chemical properties of the zeolite HY catalysts. Further, all the reduced catalyst were screened with hydroisomerization of m-xylene at LHSV = 2.0 h^-1 in the temperature range 250-400 ℃ in steps of 50 ℃ in hydrogen atmosphere (20 ml/g). The addition of Ni to Pt catalyst increases hydroisomerization conversion, as well as maximizes p-xylene selectivity by restricting the pore size. The increasing trend in activity continues up to 0.3 wt% of Ni and 0.1 wt% Pt addition over zeolite HY. The increasing addition of Ni increases the total number of active metallic sites to exposed, which increases the metallic sites/acid sites ratio towards the optimum value for these reactions by better balance of synergic effect for stable activity. The rate of deactivation is pronounced on monometallic catalysts. The results confirm the threshold Ni addition is highly suitable for hydroisomerization reaction for product selectivity over Ni-Pt bimetallic/support catalysts.

• Korean Chemical Engineering Research
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• 제57권3호
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• pp.387-391
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• 2019

A highly porous Ni@MIL-101catalyst for urea oxidation was synthesized by anchoring Ni into a Cr-based metal-organic framework, MIL-101, particles. The morphology, structure, and composition of as synthesized Ni@MIL-101 catalysts were characterized by X-Ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy. The electro-catalytic activity of the Ni@MIL-101catalysts towards urea oxidation was investigated using cyclic voltammetry. It was found that the structure of Ni@MIL-101 retained that of the parent MIL-101, featuring a high BET surface area of $916m^2g^{-1}$, and thus excellent electro-catalytic activity for urea oxidation. A $urea/H_2O_2$ fuel cell with Ni@MIL-101 as anode material exhibited an excellent performance with maximum power density of $8.7mWcm^{-2}$ with an open circuit voltage of 0.7 V. Thus, this work shows that the highly porous three-dimensional Ni@MIL-101 catalysts can be used for urea oxidation and as an efficient anode material for urea fuel cells.

• 청정기술
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• 제25권1호
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• pp.81-90
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• 2019

프로페인($C_3H_8$)의 건식 개질($CO_2$ 개질)을 통한 합성 가스($H_2$와 CO 혼합물) 제조를 위해 $Ni-CeO_2/{\gamma}-Al_2O_3$ 촉매가 충진된 유전체 장벽 방전 플라즈마 반응기를 사용하였다. 열 또는 플라즈마에 의해 환원된 $Ni-CeO_2/{\gamma}-Al_2O_3$ 촉매를 사용하여 $C_3H_8/CO_2$ 비율 1/3, 총 유량 $300mL\;min^{-1}$에서 플라즈마-촉매 건식 개질을 수행하였다. 건식 개질에 대한 촉매 활성은 온도범위 $500{\sim}600^{\circ}C$에서 평가되었다. $Ni-CeO_2/{\gamma}-Al_2O_3$ 촉매 제조를 위해 전구물질 수용액(질산니켈, 질산세륨)으로 함침된 ${\gamma}-Al_2O_3$를 공기 분위기에서 소성시킨 후, $H_2/Ar$ 분위기에서 환원시켰다. 촉매 특성 조사에는 X-선 회절분석기(XRD), 투과전자현미경(TEM), 전계 방출 주사전자현미경(FE-SEM), 승온 탈착($H_2-TPD$, $CO_2-TPD$) 및 라만 분광기가 이용되었다. 열로 환원된 촉매와 비교하면 플라즈마 방전하에서 환원된 $Ni-CeO_2/{\gamma}-Al_2O_3$ 촉매가 개질 반응을 통한 합성 가스 생산에서 보다 우수한 촉매 활성을 나타내었다. 또한, 플라즈마로 환원된 $Ni-CeO_2/{\gamma}-Al_2O_3$가 개질 반응의 문제점인 탄소퇴적 관점에서 장기 촉매 안정성을 보여주었다.

• 한국결정학회지
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• 제12권1호
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• pp.20-24
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• 2001

NiZn-ferrite was synthesized usign waste iron oxide catalysts which were produced from styrene monomer process and buried underground as an industrial wastes. The spinel type ferrite was obtained by calcination and sintering of the mixture of finely ground waste catalysts, nickel oxide and zinc oxide powders. The sintered body of Ni/sub 0.5/Zn/sub 0.5/Fe₂O₄ composition at 1230℃ for 5 hours showed the density of 5.38g/㎤, and initial permeability of 59 at 1 kHz. Not only cerium oxide, which existed as a major component in the catalyst, but also unicorporated NiO and ZnO into spinel structure remained as second phases after sintering.

• 한국전기전자재료학회논문지
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• 제14권9호
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• pp.751-756
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• 2001

Carbon nanotubes(CNTs) was successfully grown on Ni coated silicon wafer substrate by PECVD technique(Plasma Enhanced Chemical Vapor Deposition). As a catalyst, Ni thin film of thickness ranging from 15∼30nm was prepared by electron beam evaporator system. In order to find the find the optimum growth condition, initially two different types of gas mixtures such as C$_2$H$_2$-NH$_3$ and C$_2$H$_2$-NH$_3$-Ar were systematically investigated by adjusting the gas mixing ratio in temperature of 600$^{\circ}C$ under 0.4 torr. The diameter of the grown CNTs was 40∼200nm. The diameter of the CNTs increases with increasing the Ni particles size. TEM images clearly demonstrated synthesized nanotubes to be multiwalled.

• 한국분말재료학회지
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• 제12권2호
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• pp.151-158
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• 2005

Porous graphite was synthesized by removal of template in HF after pyrolysis of pyrolyzed fuel oil (PFO) at $900^{\circ}C$ using the template of Co or Ni intercalated magadiite. Porous graphite had a plate structure like template, and d-spacing value of about 0.7 nm. The extent of crystallization of porous graphite was dependent on the contents of Co or Ni intercalated in interlayer. It can be explained that the metal such as Co and Ni acts as a promotion catalyst for graphite formation. Porous graphite shows the surface area of $328\sim477 m^2/g$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기물성,응용부문
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• pp.38-39
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• 2006

We present experimental results that regard the effects of catalyst preparation on the structural and field-emissive properties of CNTs. The CNTs used in this research have been synthesized using the inductively coupled plasma-chemical vapor deposition (ICP-CVD) method. Catalyst materials (such as Ni, Co, and Invar 426) are varied and deposited on buffer films by RF magnetron sputtering. Prior to growth of CNTs, $NH_3$ plasma etching has also been performed with varying plasma etching time and power. For all the CNTs grown, nanostructures and morphologies are analyzed using Raman spectroscopy and FESEM, in terms of buffer films, catalyst materials, and pre-treatment conditions. Furthermore, the field electron-emission of CNTs are measured and characterized in terms of the catalyst preparation environments. The CNTs grown on Nicatalyst layer would be more effectual for enhancing the growth rate and achieving the vertical-alignment of CNTs rather than other buffer materials from results of SEM study. The crystalline graphitic structure of CNTs is improved as the catalyst dot reaches a critical size. Also, the field-emission result shows that the CNTs using Ni catalyst would be more favorable for improving electron-emission capabilities of CNTs compared with other samples.

• Bulletin of the Korean Chemical Society
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• 제24권11호
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• pp.1623-1626
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• 2003

The dependency of the rate of $CO_2$ reforming of methane on the catalyst loading and the reactor size was examined at a fixed temperature of $750\;^{\circ}C$ and a fixed GHSV of 18000 mL(STP)/$g_{cat}.h$. The conversion of methane in $CO_2$reforming decreased with increase in the reactor size. The catalyst was severely deactivated with increase in the catalyst amount. The amount of carbonaceous species combustible below $550\;^{\circ}C$, determined by TPO experiments with the used catalyst samples increased with increase in the catalyst amount, which was again confirmed by XRD and TEM experiments. The increase of the carbonaceous species combustible below $550\;^{\circ}C$ may be due to the suppression of the reverse Boudouard reaction, since the $CO_2$ reforming of methane, a highly endothermic reaction, resulted in lowering the reaction temperature.