• Journal of the Korean Society of Combustion
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• v.11 no.2
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• pp.7-14
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• 2006

Catalytic combustion is one of the suitable methods for micro power source due to high energy density and it can be applied to micro structured chamber without consideration of quenching since it is flameless combustion. Catalyst loading in the micro structured combustion chamber is one of the most important issues in the development of micro catalytic combustors. In this research, to coat catalyst on the chamber wall, two methods were investigated. First, $Al_2O_3$ was selected as a support of Pt and $Pt/Al_2O_3$ was synthesized through the alumina sol-gel procedure. To improve the coating thickness and adhesion between catalyst and substrate, heat resistant and water solvable organic-inorganic hybrid binder was used. Porous silicon was also investigated as a catalyst support for platinum. Through the parametric studies of current density and etching time, fabrication process of $1{\sim}2{\mu}m$ of diameter and about $25{\mu}m$ depth pores was confirmed. Coated substrates were test in the micro channel combustor which was fabricated by the wet etching and machining of SUS 304. Using $Pt/Al_2O_3$ coated substrate and Pt coated porous silicon substrate, conversion rate of fuel was over 95 % for $H_2/Air$ premixed gas.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.435-441
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• 2012

The direct conversion of cellulose into polyols in $H_2$ was examined over Pt catalysts supported on various zeolites, viz., mordenite, Y, ferrierite, and ${\beta}$. For comparison, Pt catalysts supported on ${\gamma}-Al_2O_3$, $SiO_2-Al_2O_3$, and $SiO_2$ were also tested. The physical properties of the catalysts were probed with $N_2$ physisorption. The surface acidity was measured with temperature programmed desorption of ammonia ($NH_3$-TPD). The Pt content was quantified with inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The Pt dispersion was determined with CO chemisorptions and transmission electron microscopy (TEM). The conversion of cellulose appeared to be mainly dependent on the reaction temperature and reaction time because it depends on the concentration of $H^+$ ions reversibly formed in hot water. Pt/H-mordenite (20) showed the highest yield to polyols among the tested catalysts. Pt/H-zeolite was superior to Pt/Na-zeolite for this reaction. The polyol yield was dependent on the surface acid density and the external surface area.

• 한국연소학회:학술대회논문집
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• 2006.10a
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• pp.235-241
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• 2006

Catalytic combustion is one of the suitable methods for micro power source due to high energy density and no flame quenching. Catalyst loading in the micro structured combustion chamber is one of the most important issues in the development of micro catalytic combustors. In this research, to coat catalyst on the chamber wall, two methods were investigated. First, $Al_2O_3$ was selected as a support of Pt and $Pt/Al_2O_3$ was synthesized through the alumina sol-gel procedure. To improve the coating thickness and adhesion between catalyst and substrate, heat resistant and water solvable organic-inorganic hybrid binder was used. Porous silicon was also investigated as a catalyst support for platinum. Through the parametric studies of current density and etching time, fabrication process of $1{\sim}2{\mu}m$ of diameter and about $25{\mu}m$ depth pores was confirmed. Coated substrates were test in the micro channel combustor which was fabricated by the wet etching and machining of SUS 304. Using $Pt/Al_2O_3$ coated substrate and Pt coated porous silicon substrate, conversion rate of fuel was over 95% for $H_2$/Air premixed gas.

• Journal of Energy Engineering
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• v.8 no.2
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• pp.256-264
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• 1999

The performance of the Pt-B/cordierite catalysts (2 wt%) Pt, 70 wt% Alumina, 28 wt%) Ceria and Zirconia, B: base metal) loaded with 6∼12 wt% Mn, Cu, V, Co, Cr and Ba, respectively was studied for partial oxidation of methane reaction and compared with that of Ni loaded catalyst. As a results, it was found that Ba, Co, Cr as well as Ni loaded catalysts showed higher activity for methane partial oxidation of methane than the Mn, Cu and V loaded catalyst. But it was known that catalysts having good activity for methane showed the good activity for coke formation, too. A XRD analysis of the catalyst before and after the reaction using 5 wt% Ni/Al$_2$O$_3$) showed that there were three Ni phases. In these results, it was found that methane oxidation reaction occulted at the front of the catalyst bed consisted of NiAl$_2$O$_4$and NiO and reforming reaction occurred at the rear part of the catalyst bed consisted of reduced Ni.

• Korean Chemical Engineering Research
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• v.49 no.2
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• pp.168-174
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• 2011

Various La-based perovskite catalysts were prepared by a Pechini method, and they were applied to the low-temperature oxidation of odor compounds exhausted from waste food treatment process for effective deodorization. Quantitative and qualitative analyses of exhausted gas were conducted to measure the amount of major odor compounds with respect to operation time. A standard odor sample composed of major odor compounds was then prepared for use as a feed for oxidation reaction system. Various transition metal(M)-substituted La-based perovskite catalysts ($LaMO_{3}$: M=Cr, Mn, Fe, Co, and Ni) were prepared and applied to the oxidation of odor compounds in order to investigate the $LaNiO_3$ catalyst showed the best catalytic performance. Pt-substituted perovskite catalysts ($LaNi_{1-x}Pt_{x}O_{3}$: x=0, 0.03, 0.1, and 0.3) were then prepared for enhancing the catalytic performance. It was found that $LaNi_{0.9}Pt_{0.1}O_{3}$ catalyst served as the most efficient catalyst. Supported perovskite catalysts ($XLaNi_{0.9}Pt_{0.1}O_{3}/Al_{2}O_{3}$: X=perovskite content(wt%), 0, 10, 20, 30, 40, 50, and 100) were finally applied for the purpose of maximizing the catalytic performance of perovskite catalyst in the low-temperature oxidation reaction. Catalytic performance of $XLaNi_{0.9}Pt_{0.1}O_{3}/Al_{2}O_{3}$ catalysts showed a volcano-shaped curve with respect to perovskite content. Among the catalysts tested, $20LaNi_{0.9}Pt_{0.1}O_{3}$/$Al_{2}O_{3}$ catalyst exhibited the highest conversion of odor compounds of 88.7% at $180^{\circ}C$.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.2
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• pp.121-130
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• 1996

The catalysts composed of Pt, Pd and W as active-components, $Al_{2}O_{3}$ and $SiO_{2}$ as supports, were perpared on the honeycomb type substrate and characterized by BET, SEM, TGA, FT-IR and XRD for diesel emission control. CO, $C_{3}H_{6}$, and $SO_{2}$ oxidation was carried out over these catalysts in a fixed bed continuous flow reactor at the temperatures between 100-500.deg.C and reactant gas was composed of 10 vol.% $O_{2}$, 1 vol.% CO, 0.8 vol.% $C_{3}H_{6}$ and 88.2 vol.% $N_{2}$. It was found that under these experimental conditions, the CO, $C_{3}H_{6}$ oxidation activity of Pt-W catalyst was higher than that of any other prepared catalyst, and this catalyst had also a good inhibition effect on $SO_{2}$ oxidation. Also it was show that the influence of $SO_{2}$ on $Al_{2}O_{3}$ was more sever than that of $SO_{2}$ on $SiO_{2}$.

• Journal of Sensor Science and Technology
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• v.16 no.2
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• pp.159-164
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• 2007

Thin films of platinum were deposited on a $Al_{2}O_{3}/ONO(SiO_{2}-Si_{3}N_{4}-SiO_{2})/Si$-substrate with an 2-inch Pt(99.99 %) target at room temperature for 20, 30 and 60 min by DC magnetron sputtering, respectively X-ray diffract meter (XRD) was used to analyze the crystallanity of the thin films and field emission scanning electron microscopy (FE-SEM) was employed for the investigation on crystal growth. The densification and the grain growth of the sputtered films have a considerable effect on sputtering time and annealing temperatures. The resistance of the Pt thin films was decreased with increasing deposition time and sintering temperature. Pt micro heater thin film deposited for 60 min by DC magnetron sputtering on an $Al_{2}O_{3}$/ONO-Si substrate and annealed at $600^{\circ}C$ for 1 h in air is found to be a most suitable micro heater with a generation capacity of $350^{\circ}C$ temperature and 645 mW power at 5.0 V input voltage. Adherence of Pt thin film and $Al_{2}O_{3}$ substrate was also found excellent. This characteristic is in good agreement with the uniform densification and good crystallanity of the Pt film. Efforts are on progress to find the parameters further reduce the power consumption and the results will be presented as soon as possible.

• Applied Chemistry for Engineering
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• v.20 no.5
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• pp.522-526
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• 2009

The catalytic oxidation of 1,2-dichloribenzene (1,2-DCB) and simultaneous catalytic reduction of nitrogen oxides over the single catalyst has been investigated over various metals (Ru, Mn, Co and Fe) supported on $Al_2O_3$ and $CeO_{2}$. The activity of the different catalysts for catalytic oxidation of 1,2-dichloribenzene depended on the used metal, Ru/Co/$Al_2O_3$, Mn-Fe/CeO2 and Cr/$Al_2O_3$ (commercial catalysts) being the most actives ones. In the catalytic oxidation of chlorobenzene (CB), Ru/Co/$Al_2O_3$ is better than Pt-Pd/$Al_2O_3$, which is the well-known catalyst good for VOC oxidation. Furthermore, it has a good durability on the deactivation by $Cl_2$ and sulfur. For nitrogen oxides (NOx) removal, NOx conversion was 70% at $260^{\circ}C$.

• Journal of the Korean Electrochemical Society
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• v.11 no.1
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• pp.11-15
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• 2008

The composite membrane for direct methanol fuel cell (DMFC) was developed using $H_3O^+-{\beta}"-Al_2O_3$ powder and perfluorosulfonylfluroride copolymer (Nafion) resin. The perfluorosulfonylfluroride copolymer (Nafion) resin was mixed with $H_3O^+-{\beta}"-Al_2O_3$ powder and it was made to sheet form by hot pressing. The electrodes were prepared with 60 wt% PtRu/C and 60wt% Pt/C catalysts for anode and cathode, respectively. The morphology and the chemical composition of the composite membrane have been investigated by using SEM and EDXA, respectively. The composite membrane and $H_3O^+-{\beta}"-Al_2O_3$ were analyzed by using FT-IR and XRD. The methanol permeability of the composite membranes was also measured by gas chromatography (GC). The performance of the MEA containing the composite membrane (2wt% $H_3O^+-{\beta}"-Al_2O_3$) was higher than that of normal pure Nafion membrane at high operating temperature (e.g. $110^{\circ}C$), due to the homogenous distribution of $H_3O^+-{\beta}"-Al_2O_3$, which decreased the methanol permeability through the membrane and enhanced the water contents in the composite membrane.

• Applied Chemistry for Engineering
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• v.10 no.1
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• pp.58-66
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• 1999

The catalytic oxidation of vinyl chloride was investigated over $CrO_x$ impregnated on $Al_2O_3$ at temperature between 200 and $400^{\circ}C$. The major carbonaceous products were CO and $CO_2$, and the selectivity of $CO_2$ was gradually increased with increasing reaction temperature, while that of CO was dropped consequently. This suggests that CO is the first product which is further oxidized to $CO_2$ in the oxidation of vinyl chloride over $CrO_x/Al_2O_3$. The addition of HCl in the feed didn't affect the conversion of vinyl chloride, but the selectivity of $CO_2$ decreased by adding HCl. It implies that HCl inhibits, the complete oxidation of vinyl chloride to $CO_2$. When oxidizing vinyl chloride in dry air, significant amounts of $Cl_2$ were observed, while no $Cl_2$ was detected in the humid condition. The activities of several catalysts including various precious metals and other transition metal oxides were measured, it was found that the catalytic activity of 12% $CrO_x/Al_2O_3$ was higher than other catalysts except 1% $Pt/Al_2O_3$. The reaction rate of 12% $CrO_x/Al_2O_3$ was 1.2 times lower than that of 1% Pt/alumina, but it was 3 to 8 times more active than other catalysts for vinyl chloride oxidation at $275^{\circ}C$.