• Korean Chemical Engineering Research
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• 제61권3호
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• pp.479-486
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• 2023

본 연구에서는 메탄 습식 개질 반응용 Ni/Al₂O₃ 촉매에 첨가된 Ce_xZr_1-xO₂(CZ)가 촉매 반응 효율에 미치는 효과를 조사하였다. 반응 실험 결과, CZ 조촉매가 첨가된 Ni/Al₂O₃ 촉매는 동일 온도, 동일 steam to carbon ratio에서 Ni/Al₂O₃ 촉매보다 높은 메탄 전환율과 수소 수율을 보였다. 특성 분석 결과, 두 촉매 모두 유사한 기공 구조와 비슷한 Ni 분산도를 가지고 있어 이는 반응 효율에 영향을 미치는 요소가 아님을 확인하였다. 하지만, 라만 분광 분석결과에서 CZ 조촉매 첨가 Ni/Al₂O₃ 촉매는 Ni/Al₂O₃ 촉매와 달리 CZ상에서 oxygen vacancy가 존재하고, 이는 상대적으로 낮은 반응 온도에서 물 활성화를 촉진시키는 것으로 확인되었다. CZ 조촉매 상의 oxygen vacancy에 의한 물 활성화는 저온 영역에서 CZ 조촉매 첨가 Ni/Al₂O₃ 촉매의 습식 개질 반응 성능을 증대시켰다.

• Bulletin of the Korean Chemical Society
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• 제33권5호
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• pp.1556-1560
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• 2012

A simple highly versatile and efficient method has been developed for the three-component coupling of aldehydes, amines and alkynes to prepare propargylamines, in the presence of a catalytic amount of $BiCl_3$. The advantages of methods are high yield, mild reaction conditions, no environmental pollution and easy work up procedure.

• Bulletin of the Korean Chemical Society
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• 제32권1호
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• pp.291-295
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• 2011

The catalytic enantioselective conjugate addition reaction of $\alpha$-nitroacetate to $\alpha,\beta$-unsaturated enones promoted by chiral bifunctional organocatalysts is described. The treatment of $\alpha$-nitroacetate to $\alpha,\beta$-unsaturated enones afforded the corresponding Michael adducts with high enantioselectivity. The conjugate addition adducts are easily converted to chiral $\gamma$-nitro ketones and $\delta$-keto esters.

• Bulletin of the Korean Chemical Society
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• 제30권11호
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• pp.2697-2700
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• 2009

A $Pd(OAc)_2/(o-MeOPh)_3P$ system has been developed for the catalytic Suzuki coupling of aryl bromides with arylboronic acids. Our catalyst system covers a broad spectrum of commonly available arylboronic acids and aryl bromides to provide biaryls in very good yields. The catalyst system works very well in the synthesis of sterically hindered biaryls.

• 대한화학회지
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• 제57권5호
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• pp.591-598
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• 2013

A series of chiral prolinamide compounds with pyridine-2, 6-dicarboxylic acid moieties derived from L-proline have been designed and synthesized, their catalytic properties for direct asymmetric aldol reactions were also studied in this article. These catalysts gave the aldol product in high yield (87%) and high enantioselectivity, up to 85%, of the anti-structure at room temperature but gave disappointing results at a lower temperature or when additive was added. Conditions, including solvents, temperature and additives were screened for the reactions. Moreover, the influence of presence of water on yield and stereoselectivity was also discussed.

• Korean Journal of Chemical Engineering
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• 제35권12호
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• pp.2379-2383
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• 2018

We report a facile one-pot aqueous-phase synthesis of PdAu bimetallic nanoparticles with different Pd/Au ratio. The synthesis was conducted by co-reduction of Pd and Au precursor using ascorbic acid as a reducing agent and in the presence of polyallylamine hydrochloride (PAH). By high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) and energy-dispersive X-ray spectrometry (EDS) analyses, we found that the synthesized nanoparticles had an onion-like core/shell/shell/shell structure with Au-rich core, Pd-rich shell, Au-rich shell, and Pd shell, respectively. We also investigated the catalytic performance of the synthesized PdAu nanoparticles toward hydrogen peroxide generation reaction.

• Korean Chemical Engineering Research
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• 제45권6호
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• pp.663-668
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• 2007

$Ni/CeO_2-ZrO_2$ 촉매를 이용하여 수소 제조를 위한 메탄의 자열개질반응 특성을 조사하였다. 메탄의 자열개질반응에서 촉매의 활성과 안정성을 향상시키기 위해 알루미나가 코팅된 금속 모노리스를 사용하였으며, 금속모노리스 촉매체는 높은 반응온도에서 분말형태의 촉매에 비해 높은 메탄 전환율을 나타내었다. 자열개질반응에 있어서 $H_2O/CH_4/O_2$의 비는 전환율에 영향을 미치는 중요한 변수임을 알 수 있었다. $H_2O/CH_4$ 비가 증가함에 따라 수소 수율은 증가되고, 또한 $O_2/CH_4$ 비가 증가함에 따라 메탄 전환율은 증가하지만 수소 수율은 감소하였다. $Ni/CeO_2-ZrO_2$ 촉매에 0.5 wt%의 귀금속 촉매인 Ru 첨가로 인해 낮은 반응온도에서 촉매 활성이 향상되었다.

• Macromolecular Research
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• 제17권5호
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• pp.346-351
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• 2009

$TiCl(O-i-Pr)_3/SiO_2$ and $Ti(O-i-Pr)_4/SiO_2$ were prepared by immobilizing chlorotitanium (IV) isopropoxide ($TiCl(O-i-Pr)_3$) and titanium (IV) isopropoxide ($Ti(O-i-Pr)_4$), to pretreated silica. The effect of the polymerization reaction conditions on the catalytic activity and characteristics of the resulting PLA were investigated. The catalytic conversion, molecular weight and polydispersity index (PDI) of the PLA produced on the titanium alkoxide supported catalysts increased proportionally with the reaction temperature. When the PLA was synthesized in bulk polymerization, the PLA produced with the supported catalysts had higher molecular weight than those with homogeneous catalysts. The melting temperature of the polymer produced with silica supported alkoxide catalysts was approximately $170-180^{\circ}C$.

• 한국가스학회지
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• 제26권2호
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• pp.14-20
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• 2022

본 연구에서는 메탄올 수증기 개질 반응을 이용하여 수소를 제조할 수 있는 촉매 반응 특성을 조사하였다. 메탄의 수증기 개질 반응시 자주 사용되는 니켈, 그리고 메탄올 합성 시 자주 사용되는 구리를 주 활성금속으로 사용하였으며, 지지체로는 다공성 및 열적 안정성이 우수하고, 높은 비표면적, 약한 루이스 산점과 염기성을 가지고 있는 하이드로탈사이트를 이용함으로서 높은 활성을 가지는 촉매와 그 특성에 대해서 파악하였다. 본 연구에서는 환원성이 높은 구리금속의 촉매에서 높은 반응성을 나타내었으며, 각각의 촉매에서는 함침량이 높아질수록 메탄올 전환율 및 높은 수소 선택도를 보여 주었다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권12호
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• pp.649-653
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• 2000

We have grown carbon nanotubes by thermal chemical vapor deposition of $C_{2}H_{2}$ on catalytic metal deposited on silicon oxide substrates. Highly purified carbon nanotubes are uniformly grown on a large area of the silicon oxide substrates. It is observed that surface modification of catalytic metals deposited on substrates by either etching with dipping in a HF solution and/or $NH_{3}$ pretreatment is a crucial step for the nanotube growth prior to the reaction of $C_{2}H_{2}$ gas. The diameters of carbon naotubes could be controlled by applying the different catalytic metals.