• Journal of the Korean Institute of Gas
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• v.13 no.5
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• pp.33-38
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• 2009

Synthetic natural gas was producd by the reaction of carbon monoxide and hydrogen via methanation. Ni-Co bimetallic catalyst supported on $Al_2O_3$ for methanation was prepared using deposition-precipitation method. For the comparison, Ni, Co monometallic catalyst was prepared using the same method. The prepared catalysts were characterized by TEM, XRD and TPR and applied to methanation reaction. The catalysts prepared using deposition-precipitation method showed the high metal dispersion. The activity of Ni-Co bimetallic catalyst was higher than that of Ni, Co monometallic catalyst. TPR measurements indicated that Ni-Co bimetallic catalyst had more active hydrogen species than Ni, Co monometallic catalyst due to the synergetic effect in the presence of Ni and Co.

• 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.32 no.9
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• pp.3274-3280
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• 2011

Monodispersed porous NiO and $Co_3O_4$ microcapsules with a hollow core were synthesized using SBA-16 silica sol and PS as a hard template. The porous hollow microcapsules were characterized by XRD, TEM and $N_2$ adsorption/desorption analysis. After $H_2$ reduction of metal oxide microspheres, they were conducted as an active catalyst in the reduction of chiral butylronitrile and cyanobenzene. The mesoporous metals having a hollow structure showed a higher activity than a nonporous metal powder and an impregnated metal on the carbon support.

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.335-341
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• 2018

We report the catalytic effects of metal oxides on the $CO_2$ absorption rate in an aqueous potassium salt of ${\text\tiny{L}}-lysine-HCl$ using the vapor liquid equilibrium method. The best $CO_2$ absorption rate obtained through testing metal oxides in a highly concentrated potassium salt of amino acids (2.0 M) was identified using CuO. The recyclability of the metal oxides was tested over three cycles. The catalyst CuO was found to enhance the absorption rate of $CO_2$ by 61%. A possible mechanism was proposed based on NMR spectroscopy studies. Further, the effect of change in liquid absorbent viscosity on $CO_2$ absorption is discussed.

• Macromolecular Research
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• v.9 no.2
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• pp.71-83
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• 2001

The metallocene compounds had been applied to the polymerizations of olefins and vinyl monomers with methylaluminoxane (MAO) cocatalyst, and they have usually one transition metal atom per molecule, i.e., mononuclear metallocene. Recently it has been found that the dinuclear metallocene compounds containing two transition metal atoms exhibit the peculiar polymerization behaviors for olefins and vinyl monomers. In this article, the dinuclear metallocenes are classified into four groups of dinuclear bent-metallocene, dinuclear ansa-metallocene, dinuclear constrained geometry catalyst and dinuclear half-metallocene, and then the synthesis of dinuclear metallocene of each group as well as the polymerization behaviors for ethylene, propylene, and styrene are described.

• Journal of the Korean Ceramic Society
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• v.30 no.12
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• pp.987-992
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• 1993

In order to synthesize the heat resistance ceramics of LAS system, we studied on preparing the fine powder with homogeneity by sol-gel method using metal alkoxide. Various results were obtained depending on the composition and process. When the amount of H2O added at initial stage is higher than 10mol/$\ell$, and when the amount of catalyst is 0.1mol/$\ell$, the particle size of synthesized hydrate becomes finer. On condition that partial prehydrolysis time of TEOS is more than 50 hours, the monosized fine powder is obtained(below 1${\mu}{\textrm}{m}$).

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.246-246
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• 2012

Smart catalyst design though novel catalyst preparation methods can improve catalytic activity of transition metals on reducible oxide supports such as titania by enhancement of metal oxide interface effects. In this work, we investigated Pt nanoparticles/titania catalysts under CO oxidation reaction by using novel preparation methods in order to enhance its catalytic activity by optimizing metal oxide interface. Arc plasma deposition (APD) and metal impregnation techniques are employed to achieve Pt metal deposition on titania supports which are prepared by multi-target sputtering and Sol-gel techniques. In order to tailor metal-support interface for catalytic CO oxidation reaction, Pt nanoparticles and thin films are deposited in varying surface coverages on sputtered titania films using APD. To assess the role of oxide support at the interface, APD-Pt is deposited on sputtered and Sol-gel prepared titania films. Lastly, characteristics of APD-Pt process are compared with Pt impregnation technique. Our results show that activity of Pt nanoparticles is improved when supported over Sol-Gel prepared titania than sputtered titania film. It is suggested that this enhanced activity can be partly ascribed to a very rough titania surface with the higher free metal surface area and higher number of sites at the interface between the metal and the support. Also, APD-Pt shows superior catalytic activity under CO oxidation as compared to Pt impregnation on sputtered titania support. XPS results show that bulk oxide is formed on Pt when deposited through impregnation and has higher proportion of oxidized Pt in the form of $Pt^{2+/4+}$ oxidation states than Pt metal. APD-Pt shows, however, mild oxidation with large proportion of active Pt metal. APD-Pt also shows trend of increasing CO oxidation activity with number of shots. The activity continues to increase with surface coverage beyond 100%, thus suggesting a very rough and porous Pt films with higher active surface metal sites due to an increased surface area available for the reactant CO and $O_2$ molecules. The results suggest a novel approach for systematic investigation into metal oxide interface by rational catalysts design which can be extended to other metal-support systems in the future.

• Korean Chemical Engineering Research
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• v.51 no.1
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• pp.35-41
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• 2013

Properties of $NaBH_4$ hydrolysis reaction using Co-P-B/FeCrAlloy catalyst and the catalyst durability were studied. Co-P-B/FeCrAlloy catalyst showed low activation energy such as 25.2 kJ/mol in 5 wt% $NaBH_4$ solution, which was similar that of noble metal catalyst. The activation energy increased as the $NaBH_4$ concentration increased. Formation of gel at high concentration of $NaBH_4$ seriously affected hydrogen evolution rate and the catalyst durability. The catalyst loss decreased as reaction temperature increased due to lower gel formation when the concentration of $NaBH_4$ was over 20 wt%. Considering hydrogen generation rate and durability of catalyst, the catalyst supported with FeCrAlloy heat-treated at $1,000^{\circ}C$ without ultra vibration during dipping and calcination after catalyst dipping was best catalyst. To use catalyst more than three times in 25 wt% $NaBH_4$ solution, it should be reacted at higher temperature than $60^{\circ}C$.

• Clean Technology
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• v.24 no.2
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• pp.127-134
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• 2018

To reduce the environmental pollution by $NO_x$ from ship engine, International maritime organization (IMO) announced Tier III regulation, which is the emmision regulation of ship's exhaust gas in Emission control area (ECA). Selective catalytic reduction (SCR) process is the most commercial $De-NO_x$ system in order to meet the requirement of Tier III regulation. In generally, commercial ceramic honeycomb SCR catalyst has been installed in SCR reactor inside marine vessel engine. However, the ceramic honeycomb SCR catalyst has some serious issues such as low strength and easy destroution at high velocity of exhaust gas from the marine engine. For these reasons, we design to metallic structured catalyst in order to compensate the defects of the ceramic honeycomb catalyst for applying marine SCR system. Especially, metallic structured catalyst has many advantages such as robustness, compactness, lightness, and high thermal conductivity etc. In this study, in order to support catalyst on metal substrate, coating slurry is prepared by changing binder. we successfully fabricate the metallic structured catalyst with strong adhesion by coating, drying, and calcination process. And we carry out the SCR performance and durability such as sonication and dropping test for the prepared samples. The MFC01 shows above 95% of $NO_x$ conversion and much more robust and more stable compared to the commercial honeycomb catalyst. Based on the evaluation of characterization and performance test, we confirm that the proposed metallic structured catalyst in this study has high efficient and durability. Therefore, we suggest that the metallic structured catalyst may be a good alternative as a new type of SCR catalyst for marine SCR system.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.115.2-115.2
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• 2010

Autothermal reforming(ATR) processes of hydrocarbon liquids such as diesel fuels are spotlighted as methods to produce hydrogen for Fuel cell. However, the use of heavy hydrocarbons as feedstocks for hydrogen production causes some problems which increase the catalyst deactivation by the carbon deposition. Coking can be inhibited by increasing the water dissociation on the catalyst surface. This results in catastrophic failure of whole system. Performance degradation of diesel autothermal reforming leads to increase of undesirable hydrocarbons at reformed gases and subsequently decrease the performance. In this study, perovskite-based catalysts were investigated as alternatives to substitute the noble metal catalyst for the ATR of diesel. The investigated perovskite structure was based on LaCrO3. and metals were added at the A-site to enhance oxygen ion mobility, transition metals were doped on the B-site to enhance the reformation. Substituted Lanthanum chromium perovskite were made by aqueous combustion synthesis, which can produce high surface area. And for the homogeneous fuel supply, we made ultrasonic injection system for reforming. We compared durability of evaporation system and ultrasonic system for fuel injection.