• Bulletin of the Korean Chemical Society
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• v.20 no.1
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• pp.89-94
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• 1999

Carbon dioxide reforming of methane on Ni/γ-Al2O3 catalyst was studied. A new 10 wt% Ni/γ-Al2O3 catalyst prepared by the liquid phase oxidation method (L10O) exhibited much higher activity as well as resistances to both sintering and coke formation during the reaction than the catalyst prepared by the conventional impregnation method (D10). The electrically strong attractive interaction between nickel and support during the liquid phase oxidation process and the resultant high nickel dispersion made the L10 have superior activity and stability to the D10. To elucidate the results, the experiments with nickel catalysts on the other supports as well as 7-AI203 were performed. The effect of sodium as a promoter was also studied.

• Journal of the Korean Chemical Society
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• v.24 no.3
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• pp.183-192
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• 1980

Oxidation reactions of carbon monoxide on $SnO_2$, Sb-doped $SnO_2$, and Pt catalyst were studied. The oxidation reaction was found to be first order with respect to both CO and O$_2$ on $SnO_2$ and Sb-doped $SnO_2$ catalysts, and to be of half order on Pt catalyst. A small addition of Sb to $SnO_2$ (depant composition: 0.05∼0.1 mol %) increased the rate of oxidation. On the contrary, a large addition decreased the rate. From the rate expression of oxidation on Pt catalyst, the inhibition effect of carbon monoxide on the rate of oxidation was deduced. The experimentally obtained activatio energies were 5.7 kcal for the Sb doped $SnO_2$ catalyst (dopant composion: 0.05 mole%), and 6.4 kcal for the Pt catalyst. A possible reaction mechanism was proposed from the experimentally obtained kinetic data.

• Journal of the Korean Society of Combustion
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• v.15 no.3
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• pp.25-31
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• 2010

Combined technique of burner and DOC has been used for regeneration of Diesel Particulate Filter. Experiments has been performed to increase the temperature of engine exhaust gas to burn the collected soot in DPF at all conditions of operation of 3 liter diesel engine. Ignition temperature of soot can be successfully obtained by heats of burner flame and residual fuel oxidation at diesel oxidation catalyst even in the condition of oxygen deficiency. It is found that the load of air compressor and heat loss can be reduced to the level of practical application. It is also found that CO and THC emissions are not increase by additional combustion of regeneration burner.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.4
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• pp.515-521
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• 2004

The catalytic oxidation of volatile organic compounds (methanol. acetaldehyde) has been characterized using the copper phthalocyanine catalyst in a fixed bed flow reactor under atmospheric pressure. The catalytic activity for pretreatment conditions was examined by this reaction system. The catalytic activity was ordered as follows: metal free-PC＜Cu ($\alpha$)-PC＜Cu ($\beta$)-PC The formaldehyde, carbon monoxide as a partial oxidation product of methanol and acetaldehyde over Cu ($\alpha$)-PC catalyst were detected and the conversions of methanol and acetaldehyde were accomplished above 95% over Cu ($\alpha$) -PC, Cu ($\beta$) - PC catalyst at 35$0^{\circ}C$. The pretreated metal free -PC, Cu($\alpha$)-PC, Cu($\beta$)-PC catalysts have been characterised by TGA, EA and XRD analysis. The catalytic activity pretreated with air and $CH_3$OH mixture (P-4) or air only (P-5) was very excellent. XRD and EA results showed that Cu($\alpha$)-PC, Cu($\beta$)-PC were destroyed an(1 new metal oxide such as CuO were formed.

• Bulletin of the Korean Chemical Society
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• v.23 no.3
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• pp.503-506
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• 2002

• International Journal of Automotive Technology
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• v.7 no.5
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• pp.527-534
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• 2006

Modern passenger cars with diesel engines are equipped with DOC(diesel oxidation catalyst) for the purpose of reducing HC and CO in the exhaust stream. Cold start exhaust emissions pose troubles here as on gasoline engine vehicles. As a result, some of the diesel passenger cars roll off todays the assembly lines with WCC(warm-up catalytic converter). Oxidation characteristics of the particulates in WCC is analyzed in this study by EEPS(engine exhaust particulate size spectrometer). The maximum number of PM is found to come out of WCC in sizes near 10nm when an HSDI diesel engine is operated under the conditions of high speed and medium to heavy load. When the temperature of the WCC exceeds $300^{\circ}C$, the number of PM smaller than 30 nm in diameter sharply increases upon passing through the WCC. Total mass of emitted PM gets reduced downstream of the WCC under low speed and light load conditions due to adsorption of PM onto the catalyst. Under conditions of high speed and medium to heavy load, the relatively large PM shrink or break into fine particles during oxidation process within the WCC, which results in more mass fraction of fine particles downstream of the WCC.

• International Journal of Automotive Technology
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• v.7 no.6
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• pp.653-658
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• 2006

The enormous increase in the use of fossil energy sources throughout the world has caused severe air pollution and a depletion of energy. Besides, it seems very difficult to comply with the upcoming stringent emission standards in vehicles. In order to develop low emission engines, research on better qualified fuels as alternative fuels to secure high engine performance becomes a more important issue than ever. Since sulfur contained in diesel fuel is transformed in sulfate-laden particulate matters when a catalyst is applied, it is necessary to provide low sulfur fuels before any Pt-based oxidation catalysts are applied. But the excessive reduction of sulfur levels may cause the lubricity of fuel and engine performance to degrade. In this aspect, biodiesel fuel derived from rice bran is applied to compensate viscosity lost in the desulfurization treatment. This research is focused on the performance of an 11,000cc diesel engine and the emission characteristics by the introduction of ULSD(Ultra Low Sulfur Diesel), BD20(Diesel 80%+Biodiesel 20%) and a diesel oxidation catalyst, where BD20 is used to improve the lubricity of fuel in fuel injection systems as fuel additives or alternative fuels.

• Molecules and Cells
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• v.21 no.1
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• pp.161-165
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• 2006

Dichlorodihydrofluorescein ($DCFH_2$) is a widely used probe for intracellular $H_2O_2$. However, $H_2O_2$ can oxidize $DCFH_2$ only in the presence of a catalyst, whose identity in cells has not been clearly defined. We compared the peroxidase activity of Cu,Zn-superoxide dismutase (CuZnSOD), cytochrome c, horseradish peroxidase (HRP), $Cu^{2+}$, and $Fe^{3+}$ under various conditions to identify an intracellular catalyst. Enormous increase by bicarbonate in the rate of $DCFH_2$ oxidation distinguished CuZnSOD from cytochrome c and HRP. Cyanide inhibited the reaction catalyzed by CuZnSOD but accelerated that by $Cu^{2+}$ and $Fe^{3+}$. Oxidation of $DCFH_2$ by $H_2O_2$ in the presence of a cell lysate was also enhanced by bicarbonate and inhibited by cyanide. Confocal microscopy of $H_2O_2$-treated cells showed enhanced DCF fluorescence in the presence of bicarbonate and attenuated fluorescence for the cells pre-incubated with KCN. Moreover, DCF fluorescence was intensified in CuZnSOD-transfected HaCaT and RAW 264.7 cells. We propose that CuZnSOD is a potential intracellular catalyst for the $H_2O_2$-dependent oxidation of $DCFH_2$.

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2461-2465
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• 2013

Pd-$Ce/{\gamma}-Al_2O_3-TiO_2$ catalysts were prepared by combined sol-gel and impregnation methods. Transmission electron microscopy, X-ray diffraction, $H_2$-temperature-programmed reduction, $O_2$-temperature-programmed desorption, and ethanol oxidation experiments were conducted to determine the properties of the catalysts. Addition of an optimal amount of Ce improved the performance of the $Pd/{\gamma}-Al_2O_3-TiO_2$ catalyst in promoting the complete oxidation of ethanol. The catalyst with 1% Ce exhibited the highest activity, and catalyzed complete oxidation of ethanol at $175^{\circ}C$; its selectivity to $CO_2$ reached 87%. Characterization results show that addition of appropriate amount of Ce could enrich the PdO species, and weaken the Pd-O bonds, thus enhancing oxidation ability of the catalyst. Meanwhile, the introduction of $CeO_2$ could make PdO better dispersed on ${\gamma}-Al_2O_3-TiO_2$, which is beneficial for the improvement of the catalytic oxidation activity.

• Journal of the Korea Safety Management & Science
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• v.2 no.4
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• pp.187-195
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• 2000

Electrochemical promotion of the reaction rate was investigated for CO oxidation in a solid electrolyte catalytic reactor where a thin film of Pt was deposited on the yttria stabilized zirconia as an electrode as well as a catalyst. It was shown under open circuit condition that potential was a mixed potential of $O_2$exchange reaction and electrochemical reaction induced by CO. The effect of electrochemical modification on the CO oxidation rate was studied at various overpotentials and $P_{CO}$$P_{O2}$.