• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2257-2262
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• 2014

$C_{60}$ is widely investigated because of its unique structure. But its applications in solid propellant seem to be relatively neglected. $C_{60}$ has more outstanding features than carbon black which is widely used as a catalyst ingredient of solid propellant. To combine the advantages of fullerene and lead salts, another good composite in propellant catalysts, we synthesized a kind of fullerene phenylalanine lead salt (FPL) and explored its thermal performances by differential thermal analysis (DTA) and thermogravimetry analysis (TGA). The results show it undergoes four exothermic processes started from 408 K. Combined TGA and X-ray diffractometer (XRD), the decomposition mechanism of FPL was derived by TG-IR and comparing IR spectra of FPL and its residues after burned to $327^{\circ}C$, $376^{\circ}C$ and $424^{\circ}C$, respectively. Effect of FPL on the decomposition characteristic of hexogen (RDX), a type of explosive in propellant, has been investigated using DTA at different heating rate, which shows the decomposition temperatures of the explosive are all reduced by more than 20 K. The corresponding activation energy ($E_a$) is decreased by $30kJ{\cdot}mol^{-1}$. So FPL has potential application as a combustion catalyst in solid propellant.

• 청정기술
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• 제26권4호
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• pp.286-292
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• 2020

본 연구는 Cu/CeO2-X 촉매의 저온 CO 산화 활성에 미치는 영향을 촉매의 구조적 특성, 반응 특성을 통해 확인하였다. 사용된 촉매는 습윤 함침법으로 제조되었으며, 각기 다른 소성온도(300~600 ℃)에서 형성된 CeO2 (지지체)를 이용하여 Cu (활성금속)를 담지함으로써 Cu/CeO2-X 촉매를 제조하였다. 제조된 Cu/CeO2-X 촉매는 저온 CO 산화 활성을 평가하였다. 125 ℃에서 Cu/CeO2_300 촉매는 90% 이상의 활성을 나타냈으며, CeO2의 소성온도가 증가됨에 따라 활성이 점차 감소하여, Cu/CeO2_600 촉매는 65%를 나타냈다. 다음으로 촉매의 물리/화학적 특성을 Raman, BET, XRD, H2-TPR, XPS 분석으로 확인하였다. XPS 분석 결과, CeO2-X의 소성온도가 낮을 수록 불안정한 Ce3+ 종(비 화학양론 종) 비율이 증가하였다. 증가된 Ce3+종은 Cu와 결합함으로 써 치환결합을 형성하였으며 Raman 분석의 CeO2 peak 변화와 H2-TPR 분석의 치환결합 구조의 환원 peak를 통해 확인하였다. 결과적으로 Cu와 CeO2의 치환 결합 형성은 촉매의 redox 특성 및 저온 CO 산화 활성을 증진시켰다고 판단된다.

• 한국수소및신에너지학회논문집
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• 제21권5호
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• pp.412-418
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• 2010

Steam reforming of n-hexadecane, a major component of diesel over Ni-based hydrotalcite-like catalyst was carried out at $900^{\circ}C$ at atmospheric pressure with space velocity of $10,000h^{-1}$ and feed molar ratio of steam/carbon=3.0. Ni-based hydrotalcite catalyst was prepared by a solid phase crystallization (spc) method and characterized by $N_2$-physisorption, CO chemisorption, TPR., XRD, and TEM techniques. It was found that spc Ni/MgAl catalyst showed higher catalytic stability and inhibition of carbon formation than Ni/$\gamma-Al_2O_3$ catalyst under the tested conditions. The results suggest that the modified spc-Ni/MgAl catalyst after optimization may be applied for the SR reaction of diesel.

• 신재생에너지
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• 제10권2호
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• pp.12-18
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• 2014

The objective of this work is to produce solid biofuel from sawdust using the HTC (Hydrothermal carbonization) process. The HTC process of feedstock involves the raw material coming into contact with high temperature and pressurized water. The HTC process could produce gaseous, liquefied and solid products, but this study focused on solid product only as an alternative to coal. In this study, sawdust used for a feedstock and its moisture content was under 5%. Water was added with the feedstock to raise moisture content to 80% and also used catalysts. The HTC process was performed at temperature range from 200 to $270^{\circ}C$ and reaction time was 15 to 120 min. Rising temperature resulted in increasing the higher heating value (HHV) of HTC product. In case of adding catalyst, HHV of solid biofuel was higher and reaction occurred at lower temperature and pressure. Also, HTC solid product had been characterized and found to be hydrophobic, increased HHV (over 40%), and pelletized easily compared to raw material.

• 통합자연과학논문집
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• 제4권3호
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• pp.177-181
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• 2011

The catalytic dehydrocoupling of bis(1-sila-3-butyl)benzene 1 and 2-phenyl-1,3-disilapropane 2 by $Cp_2ZrCl_2$/Red-Al and $Cp_2ZrCl_2$/n-BuLi was reported to compare their catalytic efficiency. The dehydrocoupling of monomeric silanes 1 with the $Cp_2ZrCl_2$/Red-Al and $Cp_2ZrCl_2$/n-BuLi combination catalysts produced two phases of polymers: one is a highly cross-linked insoluble solid, and the other is noncross-linked or slightly cross-linked soluble oil and could be a precursor for the solid polymer. The dehydrocoupling of 2 with the $Cp_2ZrCl_2$/n-BuLi combination catalyst similarly produced two phases of polymers. By contrast, the catalytic reaction of 2 with the $Cp_2ZrCl_2$/Red-Al combination catalyst produced a soluble polymer via redistribution/dehydrocoupling process.

• Korean Chemical Engineering Research
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• 제57권5호
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• pp.596-605
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• 2019

프로톤 전도성 세라믹인 페로브스카이트 구조의 산화물은 고온 환경에서 고체 전해질 및 촉매로써 동시에 활용이 가능하여, 반응과 분리기능을 동시에 갖춘 멤브레인 반응기로 적용하기에 우수한 소재이다. 특히 수소 제조 촉매와 분리, 이를 결합한 멤브레인 반응기 개발에 관한 연구는 전해질 내 도핑 금속의 종류 및 온도, 반응물의 조성 등에 따라 다양한 연구 결과가 제시되고 있다. 이에 본 총설에서는 프로톤 전도성 세라믹반응기에서 메탄을 활용하여 수소 제조촉매와 멤브레인 반응기로 응용해 온 연구 동향을 살펴보고, 차세대 수소의 제조와 분리 기술로서의 응용분야 및 전망에 관해 고찰하고자 한다.

• 한국자동차공학회논문집
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• 제5권4호
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• pp.179-189
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• 1997

Among aftertreatment devices which reduce exhaust gas of diesel engine, diesel oxidation catalyst(DOC) with high reduction efficiency for gaseous matter and particulate matter is now studied actively. In this study, a transient one-dimensional model developed to simulate the thermal and conversion characteristics of adiabatic monolithic converters operating under warm up conditions is presented. This model takes into account the gas solid heat and mass transfer, axial heat conduction, chemical reactions and the related heat release. The model has been used to analyze the transient response of an axisymmetric catalytic converter during a warm-up as a function of catalyst design parameters and operation conditions in order to observe their effects on the lightoff behaviour. The experimental test was carried out 2400 cc light diesel engine with DOC.

• Advances in Energy Research
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• 제1권1호
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• pp.53-78
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• 2013

Methane carbon dioxide reforming (MCDR) is a promising way of utilizing greenhouse gas for hydrogen-rich fuel production. Compared with other types of reactors, Compact Reformers (CRs) are efficient for fuel processing. In a CR, a thin solid plate is placed between two porous catalyst layers to enable efficient heat transfer between the two catalyst layers. In this study, the physical and chemical processes of MCDR in a CR are studied numerically with a 2D numerical model. The model considers the multi-component gas transport and heat transfer in the fuel channel and the porous catalyst layer, and the MCDR reaction kinetics in the catalyst layer. The finite volume method (FVM) is used for discretizing the governing equations. The SIMPLEC algorithm is used to couple the pressure and the velocity. Parametrical simulations are conducted to analyze in detail the effects of various operating/structural parameters on the fuel processing behavior.

• Bulletin of the Korean Chemical Society
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• 제33권7호
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• pp.2140-2144
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• 2012

A polymer support immobilized acidic ionic liquid was prepared by copolymerization of 3-vinyl-1-(4-sulfonic acid)butylimidazolium hydrogen sulfate with styrene in the presence of benzoyl peroxide and its primary application as a solid acidic heterogeneous catalyst to the synthesis of Hantzsch 1,4-dihydropyridines through a one-pot three-component reaction of aromatic aldehydes, ethyl acetoacetate and ammonium acetate was investigated. The results showed that this heterogeneous catalyst has high catalytic activity and the desired products were obtained in good to high yields. Moreover, the catalyst was found to be reusable and a considerable catalytic activity still could be achieved after third run.

• 대한화학회지
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• 제55권4호
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• pp.633-637
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• 2011

알코올과 페놀 계 화합물을 아실화시키는 반응에서, iron (III) phosphate 촉매를 사용했을 때에, 좋은 수율로 아실화 화합물을 얻었다. Iron (III) phosphate 촉매는 또한 친환경 반응에 재사용할 수 있는 친환경 촉매이다.