• 한국산업융합학회 논문집
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• 제6권4호
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• pp.269-275
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• 2003

A non-thermal plasma process combined with $Cr_2O_3/TiO_2$ catalyst was applied to the decomposition of trichloroethylene (TCE). A dielectric barrier discharge reactor operated with AC high voltage was used as the non-thermal plasma reactor. The effects of reaction temperature and input power on the decomposition of TCE and the formation of byproducts including HCl, $Cl_2$, CO, NO, $NO_2$ and $O_3$ were examined. At an identical input power, the increase in the reaction temperature from 373 K to 473 K decreased the decomposition of TCE in the plasma reactor. The presence of the catalyst downstream the plasma reactor not only enhanced the decomposition of TCE but also affected the distribution of byproducts, significantly. However, synergistic effect as a result of the combination of non-thermal plasma with catalyst was not observed, i.e., the TCE decomposition efficiency in this plasma-catalyst combination system was almost similar to the sum of those obtained with each process.

• International Journal of Advanced Culture Technology
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• 제3권2호
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• pp.110-117
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• 2015

10 wt% (Ni-Co) catalysts with different Ni and Co content : 10%Ni, 9%Ni1%Co, 7%Ni3%Co, 5%Ni5%Co, 3%Ni7%Co, and 10%Co; were prepared using sol-gel method followed by incipient wetness impregnation method. To investigate the catalytic activity including the stability, dry methane reforming were demonstrated over the pelletized catalysts at $620^{\circ}C$ under atmospheric pressure in a $CH_4:CO_2:N_2$ feedstock for 360 min. The results showed that bimetallic catalysts with the Co content equal to or greater than 3% were more stable than monometallic catalysts (10%Ni and 10%Co). The temperature programmed hydrogenation interpreted that the additional of Co into Ni catalyst improved the carbon resistance from methane cracking. Promoted this type of bimetallic catalyst using 1wt% K (trimetallic catalyst) prevented the carbon formation on the catalyst. The temperature programmed desorption of $CO_2$ indicated that this trimetallic catalyst has a greater number of strong basic sites. Moreover, the appearance of K lowered the number of weak basic sites and decreased the conversion of methane by 12 %.

• Bulletin of the Korean Chemical Society
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• 제24권1호
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• pp.86-90
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• 2003

Reverse-Water-Gas-Shift reaction (RWGSR) was carried out over the ZnO, $Al_2O_3,\;and\;ZnO/Al_2O_3$ catalysts at the temperature range from 400 to 700 ℃. The ZnO showed good specific reaction activity but this catalyst was deactivated. All the catalysts except the $ZnO/Al_2O_3$ catalyst (850 ℃) showed low stability for the RWGSR and was deactivated at the reaction temperature of 600 ℃. The $ZnO/Al_2O_3$ catalyst calcined at 850 ℃ was stable during 210 hrs under the reaction conditions of 600 ℃ and 150,000 GHSV, showing CO selectivity of 100% even at the pressure of 5 atm. The high stability of the $ZnO/Al_2O_3$ catalyst (850 ℃) was attributed to the prevention of ZnO reduction by the formation of $ZnAl_2O_4$ spinel structure. The spinel structure of $ZnAl_2O_4$ phase in the $ZnO/Al_2O_3$ catalyst calcined at 850 ℃ was confirmed by XRD and electron diffraction.

• 한국자동차공학회논문집
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• 제12권3호
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• pp.83-90
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• 2004

Plasma/catalyst combined reactor was designed to overcome the limits of plasma and catalyst technologies. Optimum reductant and catalyst was selected from screening test. Experiments about the concentrations of reactant and $H_2O$ and the effect of temperature were carried out. Hydrocarbons with double bond such as propylene and so on were more reactive than any other reductants in plasma/catalyst condition. Photocatalyst, especially hombikat >$TiO_2$ with the largest surface area among the catalysts tested, showed the highest DeNOx efficiency in plasma/catalyst reaction. As the concentration of $H_2O$ increased, the removal of NO was enhanced. The increased concentration of >$O_2$ promoted the reaction of NO which was oxidized to$NO_2$.

• 한국환경과학회지
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• 제18권10호
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• pp.1071-1077
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• 2009

A novel pretreatment technique was applied to the conventional Pt/alumina catalyst to prepare for the highly efficient catalyst for the preferential oxidation of carbon monoxide in hydrogen-rich condition. Their performance was investigated by selective CO oxidation reaction. CO conversion with the oxygen-treated Pt/Alumina catalyst increased remarkably especially at the low temperature below $100^{\circ}C$. This result is promising for the normal operation of the proton exchange membrane fuel cell (PEMFC) without CO poisoning of the anode catalyst. XRD analysis results showed that metallic Pt peaks were not observed for the oxygen-treated catalyst. This implies that well dispersed small Pt particles exist on the catalyst. This result was continued by high resolution transmission electron microscopy (HRTEM) analysis. Consequently, it can be concluded that highly dispersed Pt nanoparticles could be prepared by the novel pretreatment technique and thus, CO conversion could be increased considerably especially at the low temperatures below $100^{\circ}C$.

• 공업화학
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• 제26권3호
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• pp.351-355
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• 2015

호기성 벤질 알코올 산화반응을 위하여 팔라듐이 담지된 이산화티타늄 촉매를 제조하였다. 반응점으로 사용되는 팔라듐 입자의 특성을 조절하기 위하여 8종류의 상온 이온성액체를 촉매 합성 시 사용하였다. 최적의 촉매특성을 규명하기 위하여 300, $400^{\circ}C$ 및 $500^{\circ}C$로 소성하여 반응을 수행하였다. 소성온도가 증가할수록 비표면적과 기공부피가 감소 하였지만, 기공크기는 커다란 변화가 없었다. 그러나 사용한 이온성액체의 종류에 따라 촉매의 물리적 특성은 다르게 나타났다. 동일한 반응조건에서 사용한 이온성액체와 소성온도에 따라 촉매의 반응활성에 차이를 보였다. 대부분의 경우 $400^{\circ}C$에서 소성한 촉매가 우수한 반응활성을 보였다. 하지만 1-Octyl-3-methylimidazolium hexafluorophosphate 와 1-Octyl-3-methylimidazolium trifluoromethanesulfonate를 이용하여 제조한 촉매의 경우 $300^{\circ}C$에서 소성한 경우 반응활성이 우수하였다. 본 실험에서 사용한 촉매들 중에서 1-Octyl-3-methylimidazolium tetrafluoroborate를 사용하고 $400^{\circ}C$에서 소성한 촉매가 가장 우수한 반응활성을 보였다.

• 공업화학
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• 제24권3호
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• pp.320-326
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• 2013

본 연구에서는 저온경화 공정으로 합성한 다양한 폴리이미드의 물성 변화를 이해하기 위하여 4,4'-oxydianiline (ODA) 단일 다이아민(diamine)에 여러 가지 주쇄(backbone)를 가지는 산무수물(dianhydride)들을 [4,4'-oxydiphthalicanhydride (ODPA), 4,4-hexafluoroisopropylidenediphthalic dianhydride (6FDA), 3,3', 4,4'-benzophenonetetracarboxylic dianhydride (BTDA)]사용하였다. 폴리아믹산(poly(amic acid); PAA)의 합성 후, 저온경화 촉매인 1,4-diazabicyclo[2.2.2]octane (DABCO)를 여러 wt%로 첨가하여 폴리이미드 박막을 제작하고 촉매를 넣지 않은 박막과 FT-IR, UV-Vis 투과도, DSC/TGA, WAXD 분석을 통해 그 특성 변화를 비교 분석하였다. 촉매를 이용한 폴리이미드의 저온경화 시 산무수물의 종류에 따라 광학특성 및 열특성 변화량의 차이가 나타났고, 이는 촉매에 의한 mean intermolecular distance의 감소량이 산무수물의 주쇄구조에 따라 다르기 때문으로 확인되었다. 1 wt%의 촉매를 사용 시 광학특성 증가는 최대가 되고 열특성 저하는 최소가 됨을 확인하였다. 이러한 실험결과를 통해 촉매를 이용한 저온경화 폴리이미드 박막의 특성변화는 그 화학구조와 밀접한 관련이 있음을 확인할 수 있다.

• 한국지반환경공학회 논문집
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• 제17권10호
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• pp.5-11
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• 2016

본 연구에서는 포름알데히드를 상온산화시켜 제거하는 $Pt/TiO_2$ 촉매의 상용화 인자들이 조사되었다. 활성 귀금속 함량 최적화를 위해 촉매의 백금(Pt) 담지량을 변화시켜 제조 후 성능을 평가하였으며, 그 결과 1wt% 함량이 가장 이상적인 함량임을 확인하였다. 또한 활성금속인 Pt를 환원하여 제조한 환원 촉매가 상온에서 우수한 포름알데히드 산화 능력을 나타내었다. 이를 통해 활성금속의 산화가에 따라 성능이 변화될 수 있으며, 백금의 경우 metallic Pt($Pt^0$)로 존재할수록 포름알데히드 상온산화 성능이 증진될 수 있음을 확인하였다. 촉매의 운전인자를 도출하기 위한 공간속도 영향 평가 결과 공간속도가 낮을수록 촉매량 증가에 의해 포름알데히드 전환율이 증진되는 결과를 나타내었다. 또한 공기 내 반드시 존재하는 물질인 수분의 공기 내 공존 시 영향 평가를 실시하였으며, 그 결과 수분이 공존할 때 포름알데히드 산화반응이 수분이 존재하지 않은 조건에서의 활성보다 증진되었다. 상기 결과들을 통해 어떤 추가 에너지원 없이도 포름알데히드를 제거 할 수 있는 상온산화 촉매 상용화를 위한 핵심인자들을 확인하였다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제29회 KOSCI SYMPOSIUM 논문집
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• pp.181-186
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• 2004

Catalytic combustion is one of the suitable methods which is applicable to micro heat source due to high energy density and no flame quenching. And hydrogen can be oxidized at room temperature with platinum catalyst. So hydrogen-fueled micro catalytic combustor with platinum catalyst can be good and easy-handling heat source for another micro devices. In this work we focused on general catalytic combustion characteristics of hydrogen-air premixed gas in 10mm scale catalytic combustor for the further application to micro scale. Platinum was coated on dense ceramic monolith which can be installed in simple-structured catalytic combustor. We investigated the effect of flow rate, heat loss and platinum percentage in catalyst-coated monolith on catalytic combustion performance by temperature distribution in the combustor. By those results we confirmed catalytic reactivity and estimated reaction area. And we simulated micro scale catalytic reaction by sliced monolith. The results of this work will be important design factors for micro scale catalytic combustor.

• 한국수소및신에너지학회논문집
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• 제15권3호
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• pp.244-249
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• 2004

Pd catalyst have been used in hydrogenation, oxidation, and low temperature combustion reaction. Recently, it has been candidated as a possible reagents in the partial oxidation of methanol reformers of the fuel cell. Pd catalysts, even though it is very precious and expensive, catalytic functioning is good, but it still need to be improved in the matter of durability and low catalytic activity after calcination. In this study, we synthesize the improved Pd catalyst and study their chemical functioning.