• Journal of the Korean institute of surface engineering
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• v.29 no.6
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• pp.724-727
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• 1996

Electrolytic impregnation of nickel hydroxide into porous sintered nickel plaque from various nickel solutions were carried out at room or high temperatures and current density range of 2.5mA $cm^{-2}$ to 25mA $cm^{-2}$. The morphology of the deposited surface was observed with an electron microscope and the surface products were analyzed by means of X-ray diffraction method. Nickel hydroxide was deposited in nickel nitrate electrolyte, while deposits from sulphate or chloride solutions were almost metallic nickel. The loading level of nickel hydroxide from nitrate solutions was 1.6g$cm^{-3}$ void volume and the appearance of the surface was good quality. Discharge capacity of prepared electrodes in nickel nitrate electrolyte was larger than that of the others bath. It was considered that the cell capacity was dependent on the surface roughness of active material.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.191-194
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• 2009

PtRu based and PtSn based ternary catalysts were prepared by a conventional impregnation method using NaBH4 as reducing agent. The alloy formation, crystalline size and chemical composition of the in-house catalysts were determined by XRD, TEM and EDX, respectively. The chemical compositions of in-house catalysts were quite similar to the nominal value and good alloy formations were also observed. Further, crystalline sizes of ternary catalysts were comparatively smaller than binary catalysts and were approximately 3.5 ~ 5.5 nm. The electrochemical measurements were carried out in the solution 1 M $H_2SO_4$ with 1 M $C_2H_5OH$ at room temperature. LSV results obtained that ternary catalysts were higher current densities and specific activities. Especially, in case of tungsten addition system, Pt5Sn4W/C have the highest specific activities values and was approximately 21.2 and 3.1 times higher than that of PtRu/C and PtSn/C electrocatalyst.

• Journal of the Korean Wood Science and Technology
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• v.28 no.4
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• pp.56-60
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• 2000

A new porous carbon material "woodceramics" was developed by carbonizing wood or woody materials impregnated with thermosetting resin. Steamed board and non-steamed board were made from thinned small log of Aomori Hiba (Thujopsis dolabrata S. et. Z. var. hondae M.). They were impregnated with phenol resin and sintered in a vacuum furnace at $650^{\circ}C$. In this paper, the manufacturing method of woodceramics and changes of dimension, weight and compressive strength were investigated. The changes of dimension, weight and compressive strength depend on the types of board and density.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.202-205
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• 2010

Auto ignition of hybrid rocket using $N_2O$ catalytic decomposition was studied in the present study. The hybrid rocket consists of catalytic igniter, solid fuel, combustor, and nozzle. The Ru/$Al_2O_3$ catalyst for $N_2O$ decomposition was synthesized by an impregnation method, and $N_2O$ conversion as reaction temperatures was measured. The temperature change of the catalytic ignitor was measured at the operating condition, and the possibility for the auto ignition of hybrid rocket was validated.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.829-832
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• 2004

FREP(Fiber Reinforced Epoxy Panel), the products of our company, was widely made full use of a field of the reinforced concrete. In particular, the FREP used for repair and reinforcement of the subway and tunnel is required flame retardative property. In this study, flame retardative FREP using flame retardant of non-halogen system was fabricated by impregnation method. Flame retardative grade was the third grade. Tensile strength, flexural strength, and compressive strength was 1,384, 1,298, and $1,450kg/cm^2$, respectively.

• Carbon letters
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• v.4 no.1
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• pp.24-30
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• 2003

In this study, densified 4D carbon/carbon composites were made from carbon fiber and coal tar pitch through the process of pressure impregnation and carbonization and then followed by carbonization and graphitization. To improve the oxidative resistance of the prepared carbon/carbon composites, the surface of carbon/carbon composites was coated on SiC by the pack cementation method. The SiC coated layer was created by depending on the constitution of pack powder, and reaction time of pack-cementation. The morpology of crystalline and texture of these SiC coated carbon/carbon composites were investigated by XRD, SEM/EDS observation. So the coating mechanism of pack-cementation process was proposed. The oxidative res istance were observed through the air oxidation test, and then the optimal condition of pack cementation was found by them. Besides, the oxidative mechanism of SiC formed was proposed through the observation of SiC coated surface, which was undergone by oxidation test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5365-5369
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• 2011

Silica-gold composite particles were prepared by wet chemical route including impregnation method. The effect of precursor and solvent on the preparation of silica-gold particles was investigated. When spherical silica particles and PVP and hydrogentetrachloroaurate(III) hydrate aqueous solution were used as support material and precursor solution, silica-gold composite particles with light pink color successfully obtained. Obtained composite particles were characterized using FE-SEM, FE-TEM and XRD.

• Bulletin of the Korean Chemical Society
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• v.21 no.12
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• pp.1233-1238
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• 2000

$Mo/{\gamma}-Al_2O_3catalysts$ modified with Fe, Co, and Ni were prepared by impregnation method and catalytic activity for water gas shift reaction was examined. The optimum amount of Mo loaded for the reaction was 10 wt% $MoO_3$ to ${\gamma}-Al_2O_3.$ The catalytic activity of $MoO_3/{\gamma}-Al_2O_3was$ increased by modifying with Fe, Co, and Ni in the order of Co${\thickapprox}$ Ni > Fe. The optimum amounts of Co and Ni added were 3 wt% based on CoO and NiO to 10 wt% $MoO_3/{\gamma}-Al_2O_3$, restectively. The TPR (temperature-programmed reduction) analysis revealed that the addition of Co and Ni enganced the reducibility of the catalysts. The results of both catalytic activity and TPR experiments strongly suggest that the redox property of the catalyst is an important factor in water gas shift reaction on the sulfided Mo catalysts, which could be an evidence of oxy-sulfide redox mechanism.

• Bulletin of the Korean Chemical Society
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• v.22 no.12
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• pp.1303-1308
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• 2001

A series of catalysts, NiSO4/TiO2, for ethylene dimerization was prepared by the impregnation method using aqueous solution of nickel sulfate. On the basis of the results obtained from X-ray diffraction, the addition of NiSO4 shifted the transition of TiO2 from the anatase to the rutile phase toward higher temperatures due to the interaction between NiSO4 and TiO2. Nickel sulfate supported on titania was found to be very active even at room temperature. The high catalytic activity of NiSO4/TiO2 closely correlated with the increase of acidity and acid strength due to the addition of NiSO4. It is suggested that the active sites responsible for ethylene dimerization consist of low valent nickel, Ni+, with an acid.

• Bulletin of the Korean Chemical Society
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• v.22 no.12
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• pp.1309-1315
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• 2001

Zirconium sulfate supported on zirconia catalysts were prepared by impregnation of powdered $Zr(OH)_4$ with zirconium sulfate aqueous solution followed by calcining in air at high temperature. The characterization of prepared catalysts was performed using Fourier transform infrared (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and by the measurement of surface area. The addition of zirconium sulfate to zirconia increased the phase transition temperature of $ZrO_2$ from amorphous to tetragonal due to the interaction between zirconium sulfate and zirconia, and the specific surface area and acidity of catalysts increased in proportion to the zirconium sulfate content up to 10 wt% of $Zr(SO_4)_2$. Infrared spectra of ammonia adsorbed on $Zr(SO_4)2}ZrO_2$ showed the presence of Bronsted and Lewis acid sites on the surface. $10-Zr(SO_4)_2}ZrO_2$ calcined at $600^{\circ}C$ exhibited maximum catalytic activities for 2-propanol dehydration and cumene dealkylation. The catalytic activities for both reactions were correlated with the acidity of catalysts measured by ammonia chemisorption method.