• Journal of Korean Society for Atmospheric Environment
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• v.13 no.1
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• pp.91-98
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• 1997

Y-zeolite and ${\gamma}$-Al$_2$O$_3$ were used as supports on CO and $C_3$H$_{6}$ oxidation for diesel emission control. The catalysts composed of Pd and Pt as active components were wash coated on honeycomb type ceramic substrate. The oxidation of CO and $C_3$H$_{6}$ was carried out over prepared honeycomb in a fixed bed continuous reactor in the temperature range of 20$0^{\circ}C$~50$0^{\circ}C$ and 20,000 GHSV (h$^{-1}$ ). Surface area of Y-zeolite was larger than that of ${\gamma}$-Al$_2$O$_3$ due to channel structure of Y-zeolite. Therefore, high conversion of CO and $C_3$H$_{6}$ could be obtained because of good dispersion of active metals over Y-zeolite. The honeycomb used Y-zeolite as a support showed higher $C_3$H$_{6}$ conversion than that of ${\gamma}$-Al$_2$O$_3$ due to better cracking and isomerization activity of Y-zeolite. PdPt catalyst showed high conversion of CO and $C_3$H$_{6}$ at low temperature region, 20$0^{\circ}C$~30$0^{\circ}C$, for their synergy effects. PdPt/Y-Zeolite catalyst could achieve more than 80％ conversion of $C_3$H$_{6}$ at 30$0^{\circ}C$. The use of Y-zeolite as a support increased CO and $C_3$H$_{6}$ conversion, and decreased SO$_2$ conversion very effectively. Y-zeolite found to have a good adaptability as a support for the diesel emission after treatment system.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.193-196
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• 2006

This paper presents the results of catalytic endo- to exo- isomerization of saturated poly cyclic compound. Several zeolites were tested and influences of, Si/Al ratio and Structures of the zeolites on the reaction were investigated. The results showed that Y zeolites were more active than other zeolites, because of its large pore size and relative strong acidity. In all Y zeolites with different Si/Al, Y-5.4 is best. In all the zeolites tested, Y calcined at $450^{\circ}C$ was favorable. Still now the aluminium chloride catalyst is more active than zeolites. However, considering of environmental problems, corrosion, and treatment can make the zeolite catalyst substitute the aluminium chloride catalyst.

• Journal of the Korean Applied Science and Technology
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• v.17 no.2
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• pp.139-143
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• 2000

There appeared enhancements of the conversion of methane by adding a small amount of CO in the aromatization reaction of methane using the Mo-zeolite catalyst. In case of adding $CO_{2}$, $CO_{2}$ changed to CO first, and then the conversion reaction occurred. It was observed by using isotopes as reactants that CO is related to the aromatization reaction of methane.

• Journal of Industrial Technology
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• v.29 no.A
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• pp.89-94
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• 2009

The efficiency of heterogeneous catalysts has been investigated in ozonation process for organic removal. Heterogeneous catalytic ozonation was conducted for the degradation of humic acid in the presence of Granular Activated Carbon or Zeolite as a solid catalyst. And the results were compared to those of ozonation alone and adsorption alone without ozonation. The degradation characteristics of humic acid in each process were examined with the values of pH, TOC, $UV_{254}$ and $COD_{Cr}$.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.5
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• pp.95-100
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• 2014

In hypersonic aircraft, increase of aerodynamic heat and engine heat leads heat loads in airframe. It could lead structural change of aircraft's component and malfunctioning. Endothermic fuels are liquid hydrocarbon fuels which are able to absorb the heat load by undergoing endothermic reactions. In this study, exo-tetrahydrodicyclopentadiene was selected as a model endothermic fuel and experiments on endothermic properties were investigated with pore structure controlled zeolite catalyst using metal deposition. We secured the catalyst that had better endothermic performance than commercial catalyst. The object of this study is inspect catalyst properties which have effect on heat absorption improvement. Synthetic catalyst could be applied to system that use exo-THDCP as endothermic fuel instead of other commercial catalyst.

• Bulletin of the Korean Chemical Society
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• v.35 no.12
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• pp.3576-3582
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• 2014

Zeolite-templated carbons (ZTCs), which have high specific surface area, were prepared by a conventional templating method using microporous zeolite-Y for catalyst supports in direct methanol fuel cells. The ZTCs were synthesized at different temperatures to investigate the characteristics of the surface produced and their electrochemical properties. Thereafter, Pt-Ru was deposited at different carbonization temperatures by a chemical reduction method. The crystalline and structural features were investigated using X-ray diffraction and scanning electron microscopy. The textural properties of the ZTCs were investigated by analyzing $N_2$/77 K adsorption isotherms using the Brunauer-Emmett-Teller equation, while the micro- and meso-pore size distributions were analyzed using the Barrett-Joyner-Halenda and Harvarth-Kawazoe methods, respectively. The surface morphology was characterized using transmission electron microscopy and inductively coupled plasma-mass spectrometry. The electrochemical properties of the Pt-Ru/ZTCs catalysts were also analyzed by cyclic voltammetry measurements. From the results, the ZTCs carbonized at $900^{\circ}C$ show the highest specific surface areas. In addition, ZTC900-PR led to uniform dispersion of Pt-Ru on the ZTCs, which enhanced the electro-catalytic activity of the Pt-Ru catalysts. The particle size of ZTC900-PR catalyst is about 3.4 nm, also peak current density from the CV plot is $12.5mA/cm^2$. Therefore, electro-catalytic activity of the ZTC900-PR catalyst is higher than those of ZTC1000-PR catalyst.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.112-118
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• 2018

In order to meet the strict emission regulations for internal combustion engines based on fossil fuel, the proportion of after-treatments for vehicles and vessels is gradually increasing. Diesel engines have high power, good fuel economy, and lower $CO_2$ emissions, and their market shares are increasing in commercial vehicles and passenger cars. However, NOx is generated in the localized high-temperature combustion regions, and particulate matter is formed in the zones of diffusion combustion. LNT and urea-SCR catalysts have been developed for after-treatment of the exhaust gas to reduce NOx in diesel vehicles. This study aims to improve the NOx reduction performance of Cu SCR catalyst, which is widely used in light, medium, and heavy-duty diesel engines. The de-NOx performance of $5Cu-2ZrO_2$/93Zeolyst(Si/Al=13.7) SCR catalyst was about 5-50% higher than that of $5Cu-2ZrO_2$/93Zeolite(Si/Al=2.9) at catalyst temperatures of $300^{\circ}C$ or higher. The zeolite had lower metal dispersion than zeolyst, and the reaction rate of the catalyst decreased as the average particle size increased. The $10Cu-2ZrO_2$/88Zeolyst catalyst loaded with 10wt% Cu had the highest NOx conversion rate of 40% at $200^{\circ}C$ and about 65% at $350^{\circ}C$. The ion exchange rate of Cu ions increased with that of Al, the crystalline compound of zeolite, and the de-NOx performance was improved by 20-40% compared to other catalysts.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.2073-2080
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• 2013

In this study the effects of adding alkaline-earth (IIA) metal oxides to NiZr-loaded Zeolite Y catalysts were investigated on hydrogen rich production by ethanol steam reforming (ESR). Four kinds of alkaline-earth metal (Mg, Ca, Sr, or Ba) oxides of 3.0% by weight were loaded between the $Ni_6Zr_4O_{14}$ main catalytic species and the microporous Zeolite Y support. The characterizations of these catalysts were examined by XRD, TEM, $H_2$-TPR, $NH_3$-TPD, and XPS. Catalytic performances during ESR were found to depend on the basicity of the added alkaline-earth metal oxides and $H_2$ production and ethanol conversion were maximized to 82% and 98% respectively in 27($Ni_6Zr_4O_{14}$)3MgO/70Zeolite Y catalyst at $600^{\circ}C$. Many carbon deposits and carbon nano fibers were seen on the surface of $30Ni_6Zr_4O_{14}$/70Zeolite Y catalyst but lesser amounts were observed on alkaline-earth metal oxide-loaded 27($Ni_6Zr_4O_{14}$)3MO/70Zeolite Y catalysts in TEM photos after ESR. This study demonstrates that hydrogen yields from ESR are closely related to the acidities of catalysts and that alkaline-earth metal oxides reduce the acidities of 27($Ni_6Zr_4O_{14}$)3MO/70Zeolite Y catalysts and promote hydrogen evolution by preventing progression to hydrocarbons.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3485-3487
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• 2013

• Journal of Powder Materials
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• v.3 no.3
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• pp.153-158
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• 1996

The exhaust gas from vehicle engines and industrial boilers contains considerable amount of harmful nitrogen monoxide(NO) which causes air pollusion and acid rain. To remove NO catalytic reduction processes using Cu ion exchanged ZSM-5 zeolite have been widely studied. In this study, an attempt was made to fabricate Cu/zeolite catalyst by using high energy ball mill. The catalytic performance of ball milled Cu/ZSM-5 zeolites is analyzed and optimum copper contents was determined. The processing variables were reaction temperature and copper contents. Complete removal of NO gas was obtained at the temperature of 553 K on 10wt.% CU/ZSM-5 mechanically alloyed composite powders. Mechanically alloyed CU/ZSM-5 catalyst showed homogeneous distribution of Cu in ZSM-5.