• Clean Technology
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• v.16 no.1
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• pp.12-18
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• 2010

The object of the present study is to apply KF/MgO catalysts to remove sulfur dioxide from dibenzothiophene sulfone, a by-product of oxidative desulfurization. Potassium fluoride was deposited via an impregnation method on MgO. The effects KF loading and calcination on the characteristics of the KF/MgO catalysts were investigated through the BET surface area, XRF, XRD, and temperature-programmed desorption of $CO_2$. The catalytic performances of the samples were investigated during the decomposition of dibenzothiophene sulfone to biphenyl and sulfur dioxide gas. KF loaded on MgO prepared by the impregnation method showed high catalytic activities for the decomposition of dibenzothiophene sulfone. The higher activity of KF/MgO just dried at 373 K, avoiding the usual activation at high temperature, than that over the calcined catalyst is ascribed to increase of the amount of basic sites. The high basicity probably may be due to the coordinately unsaturated $F^-$. The simply dried 10 % KF/MgO catalyst, without the usual activation at high temperature, showed the optimal catalytic properties.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.537-544
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• 2011

This work was conducted to investigate the oxidation characteristics of methane having the highest ignition temperature among the other hydrocarbon gases using transition metal catalysts. The catalyst used for methane oxidation was manganese oxide having a various oxidation number, such as MnO, $MnO_2$, $Mn_2O_3$, $Mn_3O_4$, $Mn_4O_5$. The manganese oxide(MnxOy) catalyst is impregnated on $TiO_2$, $Al_2O_3$ for methane oxidation. To enhanced both of activity and life time of catalysts, Ni and Co was used as a promoter. In this study, various co-catalysts were synthesized by using excess wet impregnation method. The effect of reaction temperature and space velocity was measured to calculate the activity of catalysts such as, activation energy of $T_{50}$, and $T_{90}$. The life time of bi-metallic manganese mixture, such as Mn-Co and Mn-Ni catalysts, were increased more 10 % than manganese oxide catalyst, but activity of those was decreased slightly.

• Bulletin of the Korean Chemical Society
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• v.35 no.8
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• pp.2349-2356
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• 2014

The recycling technology by the catalytic conversion is one of the most promising techniques for the $CO_2$ treatment of coal burning power plant flue gases. The conversion of $CO_2$ to valuable product of $CH_4$ can be used as a fuel to run the turbine for electricity generation. Through this technique, the amount of coal needed for the combustion in a gas turbine can be reduced as well as $CO_2$ emissions. Therefore, a series of catalysts based on cerium oxide doped with copper, nickel and manganese were prepared by impregnation method. From the characterization analysis, it showed that the prepared catalysts calcined at $400^{\circ}C$ were amorphous in structure with small particle size in the range below 100 nm. Meanwhile, the catalyst particles were aggregated and agglomerated with higher surface area of $286.70m^2g^{-1}$. By increasing the calcination temperature of catalysts to $1000^{\circ}C$, the particle sizes were getting bigger (> 100 nm) and having moderate crystallinity with lower surface area ($67.90m^2g^{-1}$). From the catalytic testing among all the prepared catalysts, Mn/Ce-75/$Al_2O_3$ calcined at $400^{\circ}C$ was assigned as the most potential catalyst which gave 49.05% and 56.79% $CO_2$ conversion at reaction temperature of $100^{\circ}C$ and $200^{\circ}C$, respectively.

• Applied Chemistry for Engineering
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• v.20 no.6
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• pp.658-662
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• 2009

In this work, the amine-treated activated carbon nanotubes (A-MWNTs) were used to investigate the $CO_2$ adsorption behaviors. A-MWNTs were prepared by impregnation with amine in methanol after chemical activation methods using a KOH. The characteristics of amine-treated A-MWNTs were studied by X-ray photoelectron spectroscopy (XPS), $N_2$ adsorption, desorption isotherms at 77 K. The specific surface area and pore volume of the A-MWNTs were analyzed by BET equation, BJH method, and t-plot method. $CO_2$ capture capacity as a function of temperature was measured by temperature programmed desorption (TPD). From the results, the amine treatment increased the basicity and nitrogen content of the A-MWNTs. The $CO_2$ adsorption capacity of the amine-nontreated A-MWNTs showed the highest value at room temperature and then greatly decreased with increasing the temperature. However, the amine-treated A-MWNTs presented a softer slope with temperature compared to the amine-nontreated ones. It was due to the strong interactions between $CO_2$ and amino groups presented on the carbon surfaces studied.

• Korean Chemical Engineering Research
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• v.45 no.6
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• pp.573-581
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• 2007

The present study deals with removal of $CO_2$ using various mesoporous materials impregnated with MEA (monoethanolamine). The mesoporous materials such as MCM-41, MCM-48 and SBA-15 were synthesised and then impregnated with 30, 50 and 70 wt% of MEA, respectively. XRD, FT-IR and SEM were used to evaluate the characterization of those. From the adsorption/desorption experiments for various materials, the adsorption capacity of these materials were found in the order of MCM-41> MCM-48> SBA-15. MCM-41 impregnated with 50 wt% of MEA showed the maximum adsorption capacity of $57.1mg-CO_2/gr-sorbent$ at $40^{\circ}C$. It is nearly 8 times higher than MCM-41 without impregnation of MEA. In the multiple cycle test of 20 times, MCM-41 impregnated with 50 wt% of MEA showed a constant adsorption capacity.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.451-454
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• 2006

WGS reaction over Mo2C and ceria based catalysts was investigated to develop an alternative commercial Cu-Zn/Al2O3 catalyst for fuel processor and hydrogen station. The Mo2C catalysts were prepared by a temperature programmed method and the various metal supported cerium oxide catalysts were prepared by an Impregnation method. The catalysts were characterized by the N2 physisorption, Co chemisorption, XRD, TEM and TPR. It was found that Mo2C and 0.2wt% Pt-40wt%, Ni/CeO2 catalysts had higher activity and stability than the Cu-Zn/Al203 above $260^{\circ}C$. Moreover, CO conversion of more than 85% was observed at $280{\sim}300^{\circ}C$. But all catalysts were deactivated during the thermal cycling runs. The results suggest that these catalysts are an attractive candidate for the alternative Cu-Zn/Al2O3 catalyst for fuel processor and hydrogen station applications.

• Journal of the Korean Applied Science and Technology
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• v.27 no.1
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• pp.29-36
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• 2010

The effects of La addition to Ni/$CeO_2$ methane partial oxidation catalysts were investigated. Catalysts were prepared by the impregnation and urea methods. In the preparation of catalysts, La content was changed from 1 wt% to 3wt%. Catalysts that contain 2wt% La showed the highest methane conversion of about 80% and CO selectivity of 84% and $H_2$ selectivity of 70%. This result may be stemmed from that, when La content is 2wt%, a fluorite oxide-type structure is well formed and carbon deposition is also decreased. Among the catalysts, 2.5wt% Ni/Ce(La)Ox showed the highest catalytic activity. From the experiment of changing reaction temperature with 2.5wt% Ni/Ce(La)Ox catalyst, it was found that the optimum reaction temperature is $750^{\circ}C$ and at this temperature methane conversion was about 90%, CO and $H_2$ selectivities were 94 and 80%, respectively.

• Journal of the Korea Furniture Society
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• v.19 no.5
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• pp.358-364
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• 2008

Wood-inorganic material composite (WIC) was prepared by impregnating wood with copper sulfate ($CuSO_4\;5H_2O$) solution and by immersed wood in sodium carbonate($Na_2CO_3$) solution in order to introduce insoluble copper compounds {copper carbonate hydroxide, $CuCO_3\;Cu(OH)_2$} into the wood to give fungicidal effects in treated-wood. The weight percent gains (WPGs) of treated wood reached maximum value by impregnation of 20% copper sulfate solution and immersion in about 15% sodium carbonate solution for 24 hrs. Inorganic substances were present mainly in the lumina and cross-field pitting of tracheides. These substances were proved to be the insoluble copper carbonate hydroxide against water by the energy dispersive X-ray analyzer in conjunction with a scanning electron microscope (SEM-EDXA). The treated specimens showed high preservative effectiveness because the weight losses were hardly occurred by the fungi degradation test.

• Carbon letters
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• v.8 no.2
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• pp.120-126
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• 2007

The effect of cobalt precursor on the structure of Co supported multi-walled carbon nanotubes (MWCNTs) were studied by using X-ray photoelectron spectroscopy (XPS). MWCNTs were treated with a mixture of nitric and sulfuric acids and decorated with cobalt and/or cobalt oxides via aqueous impregnation solutions of cobalt nitrate or cobalt acetate followed by reduction in hydrogen. XPS was mainly used to investigate the phase of cobalt on MWCNTs after reduction with $H_2$ flow at $400^{\circ}C$ for 2 h. Higher cobalt-nanoparticle dispersion was found in the MWCNTS prepared via cobalt nitrate decomposition. A typical XPS spectrum of Co 2p showed the peaks at binding energy (BE) values equal to 781 and 797 eV, respectively. It is found that cobalt nitrate supported MWCNTs is more dispersive and have catalytic activity than that of cobalt acetate supported MWCNTs at same preparation condition such as concentration of precursor solution and reduction environment.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.4
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• pp.36-42
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• 2021

In this study, the impregnation of Lyocell fabrics was performed using phosphoric acid, ammonium phosphate, diammonium hydrogen, triammonium phosphate as phosphorus flame retardant, to fabricate continuous graphite fabrics using lyocell fiber. The physical and chemical structure changes were investigated by thermogravimetric, Fourier-transform infrared spectroscopy, C-nuclear magnetic resonance, X-ray diffraction, and weight analyses, By analyzing the thermal behavior of phosphorus flame retardant, conditions for the temperature, gas, and residual time of the pyrolysis process were set. Graphite fabrics with a tensile strength of 1,007.19±11.47 N/5 cm and yield of 25.3% were fabricated using continuous pyrolysis, carbonization and graphitization process.