• Elastomers and Composites
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• 제34권4호
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• pp.332-340
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• 1999

Hydrogenations of BR and NR performed by a noncatalytic method using p-toluenesulphonylhydrazide were carried out by reactive processing. The experimental procedures for carrying out the reaction were established. Two steps comprising premixing of the rubber with TSH followed by hydrogenation in compression mould were proved to be suitable. The percentages of hydrogenation attained by reactive processing were higher than those of the reaction carried out in solution at the same [TSH]/[C=C] ratio, reaction temperature and time. In-creasing the reaction temperature and reaction time resulted in increases of the percentage of hydrogenation. For BR, the maximum percentage of hydrogenation obtained was 36% at [TSH]/[C=C]=1/1.5. For NR, the highest percentage of hydrogenation was 34% at [TSH]/[C=C]=1/1.5. Cis-trans isomerisation was also observed to occur during hydrogenation of both BR and NR. Thermal stabilities of the hydrogenated BR and NR were shown to improve over those or the unhydrogenated counterparts.

• Korean Chemical Engineering Research
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• 제43권5호
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• pp.566-570
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• 2005

이중고리형 불포화탄화수소 화합물인 methylcyclopentadiene dimer(MCPD)의 수소화 및 이성화반응에 관한 연구를 행하였다. Exo 화합물은 2단계의 수소화반응 후에 이성화반응에 의해 제조되었다. 수소 1몰이 첨가되는 1차 수소화 반응은 $100^{\circ}C$이상의 반응온도에서는 다이머가 분해되어 모노머가 생성이 증가되었다. 1차 수소화 반응에 의하여 DHDMCPD[dihydrodi(methylcyclopentadiene)]가 생성된 후 2차 수소화반응을 진행하여 THDMCPD[tetrahydrodi (methylcyclopentadiene)]를 제조하였는데, 2차 반응온도조절에 의해 exo와 endo 비율이 변화되었다. 공정개선을 위하여 2단 가열반응기를 사용함으로 연속식 1, 2차 수소화 조건을 확립하였고 또한 endo THDMCPD로부터 exo 형태로 의 이성화반응에 할로겐화 알루미늄과 같은 할로겐화 금속촉매와 고체산 촉매를 사용하여 촉매의 활성을 비교하였다.

• Bulletin of the Korean Chemical Society
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• 제28권11호
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• pp.2034-2040
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• 2007

Efficient catalytic systems, where Ni or Pd is introduced in a supporting material of nanoporous carbon, have been developed for a liquid-phase hydrogenation of carboxylic acids and ketones at room temperature. It has been found that the catalysts reliably show high activities and selectivities for the hydrogenation to alcohols even in acidic conditions, and the catalytic activities depend on the preparative method of catalysts, the hydrogen pressure, the agitation rate, and the catalytic species. The hydrogenation of carboxylic acids and ketones clearly shows that the reaction rate is affected by the electronic and the steric effects, and a plausible reaction mechanism using metal hydrides as catalytic species is proposed.

• Bulletin of the Korean Chemical Society
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• 제19권7호
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• pp.733-737
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• 1998

Using an atom superposition and electron delocalization molecular orbital (ASED-MO) method, we have compared adsorption properties of adsorbates on the Pt(Ill) surface with the Pt(lll)/γ-Al203 surface in the ethylene hydrogenation reaction. In two-layer thick model systems, the calculated activation energy of the hydrogenation by the surface platinum hydride is equal to the energy by the hydride over supported platinum/γ-alumina. The transition structure on platinum is very close to the structure on the supported platinum/γ-alumina surface. Hydrogenation by the surface hydride on platinum can take place easily because the activation energy is about 0.5 eV less than hydrogenation by ethylidene. On supported platinum/,y-alumina the activation energy of the hydride mechanism is about 0.61 eV less than that of ethylidene mechanism. In one-layer thick model systems, the activation energy of hydrogenation by ethylidene is about 0.13 eV less than the activation energy of hydride reaction. The calculated activation energy by the hydride over the supported platinum y-alumina is 0. 24 eV higher than the platinum surface. We have found from this result that the catalytic properties of one-layer thick model systems have been influenced by the support but the two-layer thick model systems have not been influenced by the support.

• 한국식품과학회지
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• 제27권1호
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• pp.41-46
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• 1995

Changes of fatty acid composition and reaction rate were investigated according to reaction condition during partial hydrogenation reaction of soybean oil until its iodine value decreased from 134 to 110. The reaction conditions were varied in the range of from $170^{\circ}C$ to $210^{\circ}C$ of temperature, from 1.3 atm to 4.2 atm of pressure and from 0.005% to 0.1% of nickel concentration as catalyst. Lecithin was added in soybean oil to investigate the change of reaction rate. The result of addition of lecithin showed that reaction rate decreased to from 2 to 6 times in comparison with non-additive system.

• Bulletin of the Korean Chemical Society
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• 제4권4호
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• pp.180-183
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• 1983

The reaction of $IrClH_2(CO)(Ph_3P)_2$ ($Ph_3P$=triphenylphosphine) with acrylonitrile (AN) produces a stoichiometric amount of propionitrile (PN) at $100^{\circ}C$ under nitrogen, which suggests that the catalytic hydrogenation of AN to PN with $IrCl(CO)(Ph_3P)_2$ proceeds through the hydride route where the formation of the dihydrido complex, $IrClH_2(CO)(Ph_3P)_2$ is the initial step. The rate of the hydrogenation of AN to PN with $IrCl(CO)(Ph_3P)_2$ is decreased by the presence of excess $Cl^-$ in the reaction system, which suggests that $Cl^-$ is the dissociating ligand in the catalytic cycle. It has been also found that the rate of the hydrogenation increases with inercase both in hydrogen pressure and in concentration of free $Ph_3P$, and with decrease in AN concentration in the reaction system.

• 공업화학
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• 제19권4호
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• pp.432-438
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• 2008

Ru/C 촉매를 이용한 p-toluidine (TLD) 선택적 수소화 반응의 특성을 파악하기 위하여 반응 온도, 수소 압력, 촉매량, 반응용매 및 알카리 첨가제와 같은 공정변수들을 변화시켜가면서 반응속도와 생성물 분포에 미치는 영향을 조사하였다. TLD 수소화 반응에서 4-methylcyclohexylamine (MCHA)이 주된 생성물로 얻어졌으며 부반응물로는 bis(4-methyl cyclohexyl) amine (BMCHA)이 주로 생성되었다. MCHA는 온도와 압력의 증가에 따라 감소하였지만, 촉매량에 따라서는 증가함을 나타내었다. 용매의 변화에서는 isopropanol (IPA)에서 가장 좋은 선택도를 나타내었다. 이로부터 TLD 선택적 수소화에 대한 반응 기구를 제시하였다. 알카리염의 첨가는 BMCHA의 생성률을 낮게 하여 MCHA로의 선택도를 증가시켰으며 반응속도 또한 증가시켜주는 효과를 나타내었다.

• Bulletin of the Korean Chemical Society
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• 제29권2호
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• pp.328-334
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• 2008

The effects of catalyst preparation on the reaction route and the mechanism of biphenol (BP) hydrogenation, which consists of a long series-reaction, were studied. Pd/C catalysts were prepared by incipient wetness method and precipitation and deposition method. The reaction behaviors of the prepared catalysts and a commercial catalyst along with the final product distributions were very different. The choice of the catalyst preparation conditions during precipitation and deposition including the temperature, pH, precursor addition rate, and reducing agent also had significant effects. The reaction behaviors of the catalysts were interpreted in terms of catalyst particle size, metal distribution, and support acidities.

• Bulletin of the Korean Chemical Society
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• 제35권1호
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• pp.141-146
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• 2014

A series of bimetallic Cu-Zn/$SiO_2$ catalysts were prepared via thermal decomposition of the as-synthesized $CuZn(OH)_4(H_2SiO_3)_2{\cdot}nH_2O$ hydroxides precursors. This highly dispersed Cu-solid base catalyst is extremely effective for hydrogenation of ethyl acetate to ethanol. The reduction and oxidation features of the precursors prepared by coprecipitation method and catalysts were extensively investigated by TGA, XRD, TPR and $N_2$-adsorption techniques. Catalytic activity by ethyl acetate hydrogenation of reaction temperatures between 120 and $300^{\circ}C$, different catalyst calcination and reduction temperatures, different Cu/Zn loadings have been examined extensively. The relation between the performance for hydrogenation of ethyl acetate and the structure of the Cu-solid base catalysts with Zn loading were discussed. The detected conversion of ethyl acetate reached 81.6% with a 93.8% selectivity of ethanol. This investigation of the Cu-Zn/$SiO_2$ catalyst provides a recently proposed pathway for ethyl acetate hydrogenation reaction to produce ethanol over Cu-solid base catalysts.

• 청정기술
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• 제28권4호
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• pp.331-338
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• 2022

본 연구의 목적은 열분해연료유(pyrolysis fuel oil, PFO)에 포함된 다환 방향족 탄화수소(polycyclic aromatic hydro, PAHs) 수소화 반응용 촉매로서 Pt(1wt%)/Kieselguhr 비드 촉매 및 펠렛 촉매를 제조하는 것이다. Trickle-bed 반응기에서 PFO-cut 수소화 반응을 통한 포화 고리 화합물(saturated cyclic compound)의 수율을 최대화하기 위한 최적의 반응 온도 및 수소/PFO-cut 유량비는 각각 250℃와 1800으로 결정하였다. PFO-cut의 공간속도(LHSV)가 감소할수록 포화 고리 화합물의 수율이 증가하였다. 펠렛 촉매와 비드 촉매의 수소화 반응 성능 차이는 크지 않았다. Kieselguhr 지지체를 성형한 후에 Pt를 담지한 촉매(AI 촉매)가 kieselguhr 분말에 Pt를 담지한 후에 성형한 촉매(BI 촉매)에 비해 수소화 활성이 높았으며, 이러한 경향은 펠릿 촉매와 비드 촉매에서 공통적으로 나타났다. 이는 AI 촉매의 Pt 활성점 수가 BI 촉매 보다 많기 때문이다. 본 연구에서 제조한 촉매 중에서 AI법으로 제조된 펠렛 촉매가 제조된 촉매 중 반응 활성이 가장 우수한 것을 확인하였다. PFO-cut 수소화 반응 생성물 중 C₈~C₁₅ 범위의 고리 화합물이 대부분을 차지했으며, C11 고리 화합물의 분포도가 가장 높았다. 수소화 반응과 더불어서 분해 반응도 함께 촉진되어 생성물의 탄소수 분포가 경질 탄화수소 쪽으로 이동함을 확인하였다.