• Composites Research
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• 제32권2호
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• pp.85-89
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• 2019

나노입자에 기반한 화학 촉매 반응 효율성에는 크기, 형태 및 조성이 중요한 영향을 미치는 것으로 알려져 있다. 이에 대한 체계적인 비교를 위해 갈바닉 치환 반응을 통해 100 nm 직경의 요철형 표면 구조를 갖는 금, 백금, 팔라듐 나노플레이트에 대한 정량적인 분석 조건 형성이 가능하였으며, 4-나이트로페놀과 4-나이트로아닐린을 대상으로한 촉매 반응 진행을 분광분석법을 통해 확인할 수 있었다. 이로부터 동일 형태 및 형태에서 구성 원소에 따라 확연히 다른 Pd > Au > Pt의 촉매성 환원 반응 효율을 보임을 관찰할 수 있었으며, 기질의 형태에 따라 추가적인 영향을 받음을 관찰 가능하였다.

• Environmental Engineering Research
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• 제24권3호
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• pp.513-520
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• 2019

In this investigation, nano ZnO was sonochemically synthesized by a novel method using a methionine precursor. A narrow size distribution (41-50 nm) of nano ZnO was achieved that was immobilized on perlite and applied as a catalyst in catalytic ozonation. The catalyst was characterized by fourier transform infrared spectroscopy, BET surface area, and field emission scanning electron microscope. The ozonation of recalcitrant Remazol black 5 (RB5) di-azo dye solution by means of the synthesized catalyst was investigated in a bubble column slurry reactor. The influence of pH values (7, 9, 11), catalyst dosage (8, 12, 15, $20g\;L^{-1}$) and reaction time (10, 20, 30, 60 min) was investigated. Although the dye color was completely removed by single ozonation at a higher reaction time, the applied nanocatalyst improved the dye declorination kinetics. Also, the degradation of the hazardous aromatic fraction of the dye was enhanced five-times by catalytic ozonation at a low reaction time (10 min) and a neutral pH. The second-order kinetics was best fitted in terms of both RB5 color and its aromatic fraction removal. The total organic carbon analysis indicated a significant improvement in the mineralization of RB5 by catalytic ozonation using the nano-ZnO/perlite catalyst.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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• pp.44-44
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• 2003

Growth mechanism of carbon nanotubes(CNTs) synthesized by chemical vapor deposition is abided by two growth modes. These growth modes are classified by the position of activated catalytic metal particle in the CNTs. Growth mode can be also affected by interaction between substrate and catalytic metal and induced energy such as thermal and plasma. We studied the reaction of catalytic metal to the substrate and growth mode of CNTs. Various substrates such as Si(100), graphite plate, coming glass, sapphire and AAO membrane are used to study the relation between catalytic metal and substrate in the synthesis of CNTs. For catalytic metal, thin film was deposited on various substrate via sputtering technique with a thickness of ∼20nm and magnetic fluids with none-sized particles were dispersed on AAO membrane. After laying process on AAO membrane, it was dried at 80$^{\circ}C$ for 8 hour. Synthesizing of CNTs was carried out at 900$^{\circ}C$ in NH3/C2H2 mixture gases flow for 10minutes.

• Journal of Biosystems Engineering
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• 제24권6호
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• pp.465-472
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• 1999

To remove nitrogen oxides(NOx) in exhaust gas of diesel engine, three-way catalytic process with plasma discharger has great possibilities. Characteristics of NOx removal depends on NO conversion to NO$_2$and/or HNO$_3$due to high activation energies for NO oxidation and reduction. NOx removal efficiency by using three-way catalytic with plasma discharger indicated about 50% at 40watt power consumption condition.

• 한국자동차공학회논문집
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• 제7권8호
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• pp.83-90
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• 1999

To remove nitrogen oxides(NOx) in exhaust gas of diesel engine, three-way catalytic process with plasma discharger has great possbilities. Characteristics of NOx removal depends on NO conversion to $NO_2$ and/or $HNO_3$ due to high activation energies for NO oxidationand reduction. NOx removal efficiency by using three-way catalytic with plasma dischager indicated about 50% at 40 watt power consumption condition.

• Environmental Engineering Research
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• 제18권4호
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• pp.211-219
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• 2013

Rare-earth manganites have a great potential for environmental applications based on their chemical and physical properties. The use of rare-earth manganites as catalysts for environmentally essential reactions was reviewed. Artificial neural networks were used to assess the catalytic activity in oxidation reactions. Relative catalytic activities of the catalysts were further discussed. We concluded that cerium manganite is the most practicable catalyst for technological purposes.

• Bulletin of the Korean Chemical Society
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• 제30권8호
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• pp.1767-1770
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• 2009

The Henry (nitroaldol) reaction proceeds under mild conditions with catalytic amount of tetramethylethylenediamine (TMEDA) to afford $\beta$-nitro alkanol in considerably excellent yield. Structurally diverse aldehydes react with nitromethane in presence of 0.3 equiv of TMEDA under solvent-free condition at rt. The low catalytic loading and mild reaction condition are the key features of the catalytic method.

• Elastomers and Composites
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• 제50권3호
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• pp.217-222
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• 2015

Carbon-nickel nanocomposites were prepared by the reaction of fullerene ($C_{60}$) and nickel hydroxide in an electric furnace at $700^{\circ}C$ for 2 h. The hybrid carbon-nickel nanocomposites were characterized by X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. The kinetics and catalytic activity of the carbon-nickel nanocomposites in the reduction of 4-nitrophenol were confirmed by UV-vis spectroscopy.

• Bulletin of the Korean Chemical Society
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• 제13권3호
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• pp.252-255
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• 1992

Preparative methods for and catalytic activities of monoaza-18-crown-6 or monoaza-15-crown-5 in the reaction of 1-bromooctane with aqueous KI or NaI were investigated. Monoazacrown ethers were prepared by debenzylation of N-benzylmonoazacrown ethers, obtained from the reaction of N-benzyldiethanolamine and oligoethylene glycol ditosylate. The phase-transfer catalytic activity of N-benzylmonoazacrown ethers was higher than that of the corresponding monoazacrown ethers.

• Transactions on Electrical and Electronic Materials
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• 제16권2호
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• pp.70-73
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• 2015

Many studies have used chemical vapor deposition (CVD) to grow graphene. However, CVD is inefficient in terms of production costs, and inefficient for mass production because a transfer process using a catalytic metal is needed. In this study, graphene thin films were grown on single crystal sapphire substrates without a catalytic metal, using pulsed laser deposition (PLD) to resolve these problems. In addition, the growth of graphene using PLD was confirmed to have a close relationship with the substrate temperature.