• 한국연소학회:학술대회논문집
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• 한국연소학회 2007년도 제34회 KOSCO SYMPOSIUM 논문집
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• pp.37-44
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• 2007

A nickel foam, one of metal foams was seleced as a catalyst support instead of conventional ceramic materials. $Al_2O_3$ was coated on the surface of nickel foam to increase the surface area. $Al_2O_3$ coating process was based on sol-gel process. SEM image was obtained and $Al_2O_3$ coverage was confirmed. Combustion experiments were carried out using SUS combustor and $H_2$/air mixture. Temperatures were measured with different equivalence ratios and $H_2$ flow rates. $H_2$ conversion rates were calculated by the analysis of product gas using gas chromatography. Catalytic combustion of $H_2$ was complete and stable with Pt/$Al_2O_3$ coated nickel foam and influences of water vapor were confirmed during the beginning of combustion.

• 대한기계학회논문집A
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• 제33권3호
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• pp.237-242
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• 2009

MEMS catalytic combustors were fabricated to use in micro-power sources as a heat source. The combustor was fabricated by photolithography and anisotropic wet etching of photosensitive glass wafers. Two different catalyst loading methods were used to complete the fabrication of the combustors. For thin film type, the $Al_2O_3$ was washcoated on the surface of the combustion chamber as a catalyst support, and for packed-bed type, ceramic foam was inserted after Pt was coated. The volume of the combustors was 1.8 $cm^3$ and 16W of heat was generated using the fabricated combustors with hydrogen. The energy density of combustor was about 8.9 W/$cm^3$.

• 한국자동차공학회논문집
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• 제11권2호
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• pp.134-139
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• 2003

This study was carried out to investigate the aging and conversion characteristics of oxidation catalysts for a natural gas vehicle with lean-bum system. The conversion of $CH_4$ was observed over the various composition ratio of PMs(Precious metals) and washcoating methods. On the fresh catalysts, Pd affected on the activity of $CH_4$ at low temperature more than other PMs in Pd-only and Rh/Pd/Pt catalysts. The activity at low temperature increased as a mount of Pd increases. On the aged catalysts, the $CH_4$ conversion efficiency of Pd-only catalyst with mono-layer washcoat decreased more than that of the other catalysts of $CH_4$ conversion. It was observed that the thermal durability of Rh/Pd/Pt catalysts with double-layer washcoat was better than the single washcoat catalyst.

• 한국대기환경학회지
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• 제15권3호
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• pp.249-255
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• 1999

We sdudied effect of additives on catalytic activity in thermal catalytic de-NOx process which was composed of thermal reduction, catalytic reduction and catalytic oxidation stage. Pd-Pt/${\gamma}$-$Al_2O_3$ catalysts with the addition of transition metals(Co, Cu, Fe, Ni, W, Zn, Zr) and rare earth metals(Ce, Sr) were prepared by the conventional washcoating method. Those catalysts were characterized by CO pulse chemisorption, ICP, $N_2$ adsorption, SEM and XRD. The effect of catalyst additives on NOx removal for diesel emission was studied in thermal catalytic de-NOx process at reduction temperature(350~50$0^{\circ}C$), space velocity(5,000~20,000 $hr^{-1}$) and the engine load(0~120kW). The concentraton of CO, $CO_2$, NO and $NO_2$ in the exhaust gas increased with the engine load. On the other hand the concentration of $O_2$ decreased. The de-NOx activityof all prepared catalysts increased with respect to high CO and low $O_2$ level in the thermal reduction stage of the process. Insertion of Ce to Pt-Pd/${\gamma}$-$Al_2O_3$ catalyst showed the best activity of all the catalysts under these experimental conditions. De-NOx catalysts are effective to remove CO in addition to NOx in the catalytic reduction stage.

• 한국자동차공학회논문집
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• 제16권5호
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• pp.60-67
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• 2008

The catalytic filter of Cu-ZSM5/alumina beads was considered to reduce NOx in the urea SCR system. Catalytic support of porous alumina beads with mean pore size $130{\mu}m$ and porosity $75{\sim}83%$ were prepared using foaming and gel-casting method. The Cu-ZSM5 catalysts were coated on the supporting alumina beads using $Cu(NO_3)_2$ by ion exchange method. After a washcoating process was applied to coat 10w% Cu-ZSM5 on porous alumina bead, coating layer was estimated $20{\mu}m$ in thickness. The characterization and the feasibility as a catalytic supports were investigated. And the NOx conversion test in Cu-ZSM5/Alumina Beads filter system was conducted by using Urea as reductants under laboratory test. The NOx conversion was increased as size and porosity of beads and observed more than 95% excellent NOx conversion above $300^{\circ}C$.

• Korean Chemical Engineering Research
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• 제59권4호
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• pp.481-486
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• 2021

극초음속 비행체의 비행 중에 발생되는 열 문제를 해결하기 위해 탑재된 연료의 분해반응 시 나타나는 흡열효과를 이용하는 냉각기술이 개발되고 있다. 본 연구에서는 HZSM-5를 촉매로 사용하여 n-dodecane 연료의 분해반응을 수행하였으며, 촉매 분해반응의 흡열효과를 극대화하고 코크생성을 억제하기 위해 촉매를 메탈폼에 코팅하였다. 반응기는 외경 1.27 cm의 스테인리스 스틸 흐름형 반응기를 사용하였다. HZSM-5를 메탈폼에 코팅한 촉매를 사용한 촉매 분해반응 결과 흡열량은 최대 2887 kJ/kg, 기상전환율은 34% 이었으며, 메탈폼의 코크생성량은 촉매를 코팅함에 따라 촉매를 코팅하지 않은 것에 비해 약 56% 감소하였다.

• 한국응용과학기술학회지
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• 제36권1호
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• pp.153-164
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• 2019

본 연구에서는 기존 상용 SCR 촉매보다 비표면적, 경량성 및 온도 응답성이 우수한 SCR 촉매의 개발을 목적으로 바나듐과 텅스텐의 함량과 바인더의 첨가량을 달리하여 Metal foam 형태의 지지체에 코팅하여 SCR 촉매를 제조한 후, 실험실 규모의 마이크로 상압반응기상에서 공간속도별로 NOx 저감 성능을 측정하였다. 촉매의 특성은 Porosimeter, SEM(scanning electron microscope), EDX(energy dispersive x-ray spectrometer) 및 ICP(inductively coupled plasma), 실체현미경(Stereomicroscope) 기기를 이용하여 분석하였다. 연구 결과 NOx 저감 성능은 공간속도가 증가할수록 감소하였고, 바나듐과 텅스텐의 함량이 3.5 wt.% 일 때 가장 우수한 것으로 확인하였다. 또한, 바인더 첨가량이 많을수록 NOx 저감 성능이 감소하는 것으로 나타났는데, 이는 촉매 표면상의 활성점 수가 바인더에 의해 점유되어 감소된 것에 따른 것으로 판단된다. 또한 표면 코팅 상태 분석을 통하여 바인더의 첨가량이 적절히 조절 되어야 함을 알 수 있었다.