• Bulletin of the Korean Chemical Society
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• 제26권10호
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• pp.1512-1514
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• 2005

Catalytic properties of Ni-Zr$O_2$ catalysts prepared by coprecipitation have been studied for the gas-phase hydrogenation of 1,3-butadiene to butenes. The coprecipitation method led to the solid solution of Ni-Zr$O_2$, which contains highly resistant Ni species to thermal reduction with H2. Nickel species of the solid solution were highly dispersed in the ZrO2 lattice, so that the reduced catalysts were selective for hydrogenation of 1,3-butadiene to butenes (99.9%) even in the presence of 1-butene.

• Journal of Industrial and Engineering Chemistry
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• 제67권
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• pp.486-496
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• 2018

Bimetallic Pd@Ni nanostructure exhibited enhanced co-catalytic activity for the selective hydrogenation of benzaldehyde compare to their monometallic counterparts. Impregnation of these mono/bimetallic nanostructures on mesoporous $TiO_2$ leads to several surface modifications. The bimetallic PNT-3 ($Pd_3@Ni_1/mTiO_2$) exhibited large surface area ($212m^2g^{-1}$), and low recombination rate of the charge carriers ($e^--h^+$). The hydrogenation reaction was analyzed under controlled experiments. It was observed that under UV-light irradiations and saturated hydrogen atmosphere the bimetallic PNT-3 photocatalyst display higher rate constant $k=5.31{\times}10^{-1}h^{-1}$ owing to reduction in the barrier height which leads to efficiently transfer of electron at bimetallic/$mTiO_2$ interface.

• Bulletin of the Korean Chemical Society
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• 제18권8호
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• pp.806-810
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• 1997

A series of new hydridocarbonyl osmium(Ⅱ) complexes, OsHCl(CO)(PPh3)(L-L)[L-L=Ph2P(CH2)nPPh2 (n=1 (1), 2 (2), 3 (3), cis-Ph2PCH=CHPPh2 (4), and Fe(η5-C5H4PPh2)2 (5)] has been synthesized from OsHCl(CO)(PPh3)3 and chelating diphosphines. These complexes have been characterized by IR, 1H NMR and elemental analysis. The catalytic activities of these complexes both for the transfer hydrogenation of trans-cinnamaldehyde with 2-propanol as the hydrogen donor, and for the selective hydrogenation of trans-cinnamaldehyde with H2, have been examined. Complexes (1)-(5) were shown to have higher selectivities for the transfer hydrogenation of the C=O bond of aldehyde than for the transfer hydrogenation of the C=C bond of aldehyde. The selectivities for the transfer hydrogenation with 2-propanol as well as for the hydrogenation with H2 have been found to decrease in the order 3 > 5 > 2 > 4 > 1. Complex (3) has shown to possess almost 90% of the selectivity to cinnamyl alcohol for transfer hydrogenation. It is also found that there is a correlation between the ν(CO) of each complex and the hydrogenation, of the C=O bond of trans-cinnamaldehyde. Overall, the selectivities with the complexes (1)-(5) are greater for the transfer hydrogenation with 2-propanol than for the hydrogenation with H2.

• Bulletin of the Korean Chemical Society
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• 제23권12호
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• pp.1785-1789
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• 2002

2,2'-Dichlorohydroazobenzene was prepared by selective hydrogenation of o-nitrochlorobenzene with hydrogen in the presence of 0.8% and 5% Pd/C catalyst. O-Chloroaniline was a minor product in the catalytic hydrogenation of o-nitrochlorobenzene. The effects of base, Pd/C catalyst, and co-catalyst were discussed on catalytic hydrogenation. 2,2'-Dichlorohydroazobenzene, as an intermediate, was rearranged to 3,3'-dichlorobenzidine after reacting with HCl. It was shown that selectivity of catalytic hydrogenation of o-nitro-chlorobenzene is affected strongly by concentration of base, Pd/C catalyst, and co-catalyst. $^1Hand^{13}C$NMR spectroscopy confirmed the chemical structures of 2,2'-dichlorohydrazobenzene and 3,3'-dichlorobenzidine.

• Bulletin of the Korean Chemical Society
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• 제17권8호
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• pp.765-766
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• 1996

• Bulletin of the Korean Chemical Society
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• 제21권4호
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• pp.451-452
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• 2000

• Bulletin of the Korean Chemical Society
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• 제29권12호
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• pp.2434-2440
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• 2008

The effect of sodium (Na) promotion was studied in the biphenol (BP) hydrogenation using various Pd/C catalysts. Different amounts of sodium metal were used for promotion with Pd/C and their effects on BP hydrogenation were observed. The promotion order was changed to compare the effect of the position of the promoter in relation to the palladium (Pd) metal on the catalytic activity and yield of the final product, bicyclohexyl-4,4'-diol (BHD). Pd/C catalysts prepared from different methods were also sodium-promoted and the changes of the reaction pathway according to the type of promoted Pd/C catalyst were compared.

• Journal of Industrial and Engineering Chemistry
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• 제68권
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• pp.325-334
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• 2018

Lactose is a reducing disaccharide consisting of two different monosaccharides such as galactose and glucose. The hydrogenation of lactose to lactitol is a formidable challenge because it is a complex process and several side products are formed. In this work, we synthesized Ru-Ni bimetallic nanohybrids as efficient catalysts for selective lactose hydrogenation to give selective lactitol. Ru-Ni bimetallic nanohybrids with $Ru-NiO_x$ (x = 1, 5, and 10 wt%) are prepared by impregnating Ru and Ni salts precursors with $TiO_2$ used as support material. Ru-Ni bimetallic nanohybrids (represented as $5Ru-5NiO/TiO_2$) catalyst is found to exhibit the remarkably high selectivity of lactitol (99.4%) and turnover frequency i.e. ($374h^{-1}$). In contrast, monometallic $Ru/TiO_2$ catalyst shows poor performance with ($TOF=251h^{-1}$). The detailed characterizations confirmed a strong interaction between Ru and NiO species, demonstrating a synergistic effect on the improvement on lactitol selectivity. The impregnation-reduction method for the preparation of bimetallic $Ru-NiO/TiO_2$ catalyst promoted Ru nanoparticles dispersed on NiO and intensified the interaction between Ru and NiO species. $Ru-NiO/TiO_2$ efficiently catalyzed the hydrogenation of lactose to lactitol with high yield/selectivity at almost complete conversion of lactose at $120^{\circ}C$ and 55 bar of hydrogen ($H_2$) pressure. Moreover, $Ru-NiO/TiO_2$ catalyst could also be easily recovered and reused up to four runs without notable change in original activity.

• Korean Chemical Engineering Research
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• 제61권1호
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• pp.168-174
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• 2023

일반적인 메틸 메타아크릴레이트(methyl methacrylate) 상업 공정의 중간체인 메타아크릴 알데히드(methacryl aldehyde)에는 불순물이 존재한다. 이는 전체 화학 반응의 전환율과 선택도가 크게 저하되는 원인이며 메타아릴 알코올(methallyl alcohol) 생산성 향상의 주요 문제이다. 본 연구는 다양한 불순물 중에서 반응성 저하의 주요 원인이 산(acid)임을 발견하였다. 불순물로 존재하는 산은 촉매의 활성을 급격하게 저하시키며, 부반응인 불균일 딜스-알더 반응(hetero Diels-Alder reaction)이 촉진됨을 확인하였다. 따라서, 메타아크릴 알데히드의 카르보닐기(carbonyl group)를 선택적으로 수소화하는 반응에서 반응 불순물인 산을 제거하기 위해 전처리 방법을 비교 평가하였고, 생산성을 향상시키기 위한 효과적인 방법을 제안하였다. 이를 통해 제안된 조건 하에서 최적의 선택적 수소화 반응 조건을 완성하였다.

• 한국식품과학회지
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• 제22권6호
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• pp.681-685
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• 1990

반응온도 $210^{\circ}C$, 수소압력 $0.3\;kg/cm^2$, 니켈촉매량 0.12%, 교반속도 280 rpm의 선택적 수소첨가조건에서 반응이 진행됨에 따른 면실유의 지방산 조성, 트란스산 및 이화학적인 특성의 변화를 연구하였다. 지방산 조성에 있어서는 팔미트산(16 : 0), 스테아르산(18 : 0)같은 포화지방산은 거의 변함이 없었고, 리놀레산(18 : 2), ($50.03%{\rightarrow}9.38%$)이 올레산(18 : 1) ($20.65%{\rightarrow}60.35%$)으로 전환되었으며, 특히 리놀레산 이성체 변화에서는 ct, tc, tt형의 변화보다는 cc형의 변화가 현저하였고, 올레산 이성체 변화에서는 t형 생성량은 현저하게 증가한데 비해 c형의 변화는 거의 없었다. 반면, 수소첨가됨에 따라 녹는점 및 고체지함량은 직선적으로 증가하였고 요드값은 직선적으로 감소하였다. 이들의 결과로부터 다음과 같은 직선회귀식을 구하였다. 녹는점과 요드값 : Y=1.59-2.36X(r=0.96, p<0.05), 고체지함량($at\;20^{\circ}C$)과 녹는점 : Y=2.81+2.01X(r=0.96, p<0.05), 고체지함량($at\;20^{\circ}C$)과 요드값 : Y=9.40-5.16X(r=-0.99, p<0.01), 고체지함량($at\;20^{\circ}C$)과 18 : 1 t : Y=6.25+8.48X(r=0.97, p<0.05).