• 동력기계공학회지
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• 제5권2호
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• pp.13-21
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• 2001

Diesel emission control is being addressed worldwide to help preserve the global environment. This paper mainly deals with the effects of oxidation catalysts to reduce emissions from the automotive heavy-duty diesel engine. Two types of the oxidation catalyst with different kinds of precious material were used. An 11 litter displacement diesel engine with turbocharger was operated to evaluate DOC with various engine speed, load conditions under D-13 mode cycle. We could propose the detail emission data of an automotive heavy-duty diesel engine and the characteristics of the conversion efficiency of the DOC under the D-13 mode. It was found that the mean conversion efficiencies of CO and THC were 49.7% and 61% under the D-13 mode test, respectively.

• 동력기계공학회지
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• 제6권2호
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• pp.18-23
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• 2002

Recently, as people pay attention to the environmental pollution, the emission of diesel engine has become a serious problem. Diesel Oxidation Catalysts(DOC) were experimentally investigated for the purification of pollutants exhaust emission from the diesel engine. In this study, the conversion efficiency of exhaust gas was investigated with various washcoat materials of the DOC. It was formed that CO conversion efficiency depended on temperature, but THC conversion was dominated by temperature and space velocity. Conversion efficiency of THC and CO increased with the addition of ZSM-5 in the washcoat, whereas these conversion efficiency decreased by adding Nd and Ba additives. $V_2O_5$ additive had the thermal stability for high temperature. Thermal durability of the catalyst was improved as increase of $V_2O_5$ additive.

• 한국항공우주학회지
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• 제41권3호
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• pp.226-232
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• 2013

소형 무인항공기의 동력장치로 연료전지 시스템을 적용하기 위해 화학수소화합물 수소 저장방법을 이용한 소형 수소 발생 제어장치를 설계하였다. 효율이 높은 소형/경량 수소 발생 제어장치를 설계하기 위하여 $NaBH_4$ 수용액 공급 유량에 따른 Co-B 촉매의 수소 전환율을 확인하였고, 100W 스택의 최대 수소 발생량에 적합한 Co-B 촉매양을 제안하였다. 효율적인 연료 소모를 위해 Dead-end 방식의 스택을 선택하였고, 수소 발생 제어장치 내부 압력을 이용한 펌프 on/off 제어로 수소 생성량을 제어하였다. 소형 수소 발생 제어장치를 이용한 연료전지 시스템의 각 작동구간에서 안정된 운전을 확인하였다. 장시간 운전 실험을 통하여 최대 7시간 운전이 가능하며, 임의의 비행 프로화일에 요구되는 추력 프로화일은 최소 4시간 이상 조정 가능함을 확인하였다.

• 대한기계학회논문집B
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• 제34권2호
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• pp.165-171
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• 2010

HCCI 엔진은 배출가스 중 PM과 NOx 가 저감되나, 일반적으로 상용디젤 엔진보다 HC, CO 가 증가하는 특성을 보인다. 특히 과도한 HC 에서 발생하는 SOF 로 인해 total PM 에 영향을 미친다. 이는 HCCI 엔진에서 DOC 를 통한 HC 저감이 중요하며 HC 의 정화성능이 우수한 OC 의 개발이 필요하다. 실험은 모델가스를 이용하여 2Pt/1Pd 의 충전량이 다른 3 종의 OC(600cpsi cordierite)를 가지고 수행하였다. OC 에서 HC, SV, $H_2O$, $O_2$의 조건을 달리하여 OC 성능특성을 $LOT_{50}$에서 평가하였다. 그 결과 CO 는 $170^{\circ}C$에서 3 종의 촉매 모두 90% 이상의 정화특성을 나타내었고 Pd 가 충전 된 OC 는 열화 된 후 Pt 만충전 된 OC 보다 우수한 내구특성을 나타내었다. Fresh 와 aged 된 OC 에서 SV 의 증가 및 $H_2O$의 반응참여는 $LOT_{50}$성능이 낮아지는 결과를 나타내었다.

• Bulletin of the Korean Chemical Society
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• 제6권2호
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• pp.115-118
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• 1985

The oxidation of hydrazobenzene by oxygen in methanol solution is catalysed by Co(3MeOsalen) which is a synthetic oxygen carrier. The products are trans-azobenzene and water. The rate of the reaction has been studied spectrophotometrically and the rate law established. A mechanism involving a ternary complex of catalyst, hydrazobenzene and oxygen has been proposed.

• Bulletin of the Korean Chemical Society
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• 제33권6호
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• pp.1945-1948
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• 2012

Rhodamine B (RhB) and rhodamine 6G (Rh6G) were employed as catalysts for the synthesis of cyclic carbonate from carbon dioxide and epoxide. It turned out that the catalytic activity of Rh6G was nearly 29 times higher than that of RhB at 1 atm pressure, $90^{\circ}C$. Furthermore, the catalytic efficiency of RhB and Rh6G was greatly enhanced with triethylamine as co-catalyst. Under the optimized conditions, the best isolated yield (93%) of cyclic carbonate was achieved without organic solvent and metal component.

• International Journal of Automotive Technology
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• 제6권6호
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• pp.591-598
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• 2005

A three-way catalyst system of a natural gas vehicle (NGV) has characteristics of higher fuel consumption and higher thermal load than a lean-bum catalyst system. To meet stringent emission standards in the future, NGV with the lean-bum engine may need a catalyst system to reduce the amounts of HC, CO and NOx emission, although natural gas system has low emission characteristics. We conducted experiments to evaluate the conversion efficiency of the NOx reduction catalyst for the lean-burn natural gas engine. The NOx reduction catalysts were prepared with the ${\gamma}-Al_{2}O_3$ washcoat including Ba based on Pt, Pd and Rh precious metal. In the experiments, effective parameters were space velocity, spike duration of the rich condition, and the temperature of flowing model gas. From the results of the experiments, we found that the temperature for maximum NOx reduction was around $450^{\circ}C$, and the space velocity for optimum NOx reduction was around $30,000\;h^{-1}$ And we developed an evaluation model of the NOx reduction catalyst to evaluate the conversion performance of each other catalysts.

• Elastomers and Composites
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• 제50권2호
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• pp.103-109
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• 2015

In this study, epoxy/anhydride mixing ratio for the highly silica filled compounds with chromium (III) octoate catalyst was investigated at a low curing temperature ($71^{\circ}C$ for 40 hr) by evaluating the compressive strength with the weight ratio ranges from 0.3/1.0 to 1.0/1.0 of epoxy part (Part A)/anhydride part (Part B). In case of epoxy/anhydride compounds used surface unmodified silica by coupling agent, these compounds need excess anhydride unlike the weight ratio in the conventional epoxy/anhydride compounds. In curing behavior, the epoxy/anhydride compounds containing chromium (III) octoate showed high conversions at $71^{\circ}C$ for 40 hr, even if a dipropylene glycol (DPG) was not used as a polymerization initiator. Also, DPG leads to a poor epoxy network structure. In conclusion, the appropriate weight ratio of Part A/Part B of highly silica filled epoxy/anhydride compounds with chromium (III) octoate catalyst is 0.5/1.0 and the maximum amounts of silica is 1470 phr of epoxy resin.

• 공업화학
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• 제10권6호
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• pp.863-870
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• 1999

본 연구에서는 촉매로 Co-Mn-Br계를 사용하고, 상대적으로 온화한 반응조건에서 2,6-Dimethylnaphthalene(DMN)의 산화 반응 특성과 촉매가 반응에 미치는 영향을 고찰하였다. 이를 위해 $2{\ell}$의 회분식 반응기를 이용하여 촉매의 농도를 조절하며 실험하였다. 먼저 반응시간에 따른 반응중간생성물의 농도변화를 분석하여 반응경로를 확인하였고, 그 결과 2-formyl-6-naphthoic acid, 2-methyl-6-naphthoic acid, 그리고 2-hydroxymethyl-6-methylnaphthalene이 반응중간물임을 확인할 수 있었다. 또한, 2,6-naphthalene dicarboxylic acid(NDA)의 수율은 Co와 Br의 농도에 많은 영향을 받는다는 것을 알 수 있었고, 제품의 품질 척도 중 하나인 color-b는 Mn의 농도와 밀접한 관련이 있는 것으로 나타났으며, 용매연소는 Mn과 Br의 농도조절로 줄일 수가 있었다. 조촉매로 Ce/Cu 화합물을 첨가함으로 NDA의 수율을 증가시키고 용매연소를 줄이는 결과를 얻을 수 있었다.

• 고무기술
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• 제13권1호
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• pp.1-9
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• 2012

Click chemistry had enjoyed a wealthy decade after it was introduced by K.B.Sharpless and his co-worker on 2001. Since there is no optimized method for synthesis of click polymer, therefore, this paper introduced three click reaction methods such as catalyst, non-catalyst and azide-end capping for fluorene-based functional click polymers. The obtained polymers have reasonable molecular weight with narrow PDI. The polymers are thermally stable and almost emitted blue light emission. The synthesized fluorene-based functional click polymers were characterized to compare the effect of click reaction methods on polymer electro-optical properties as well as device performance on quasi-solid-state dye sensitized solar cells (DSSCs) applications. The DSSCs with configuration of $SnO_2:F/TiO_2/N719$ dye/quasi-solid-state electrolyte/Pt devices were fabricated using these click polymers as a solid-state electrolyte components. Among the devices, the catalyzed click polymer composed device exhibited a high power conversion efficiency of 4.62% under AM 1.5G illumination ($100mW/cm^2$).These click polymers are promising materials in device application and $Cu^I$-catalyst 1, 3-dipolar cycloaddition click reaction is an efficient synthetic methodology.