Fisher-Tropsch synthesis for the production of hydrocarbon from syngas was investigated on 20% cobalt-based catalysts (20% Co/HSA, 20% Co/Si-MMS), which were prepared by home-made supports with high surface areas such as high surface alumina (HSA) and silica mesopores molecular sieve (Si-MMS). In the gas phase reaction by syngas only, 20% Co/Si-MMS catalyst was shown in higher CO conversion and lower carbon dioxide formation than 20% Co/HSA, whereas the olefin selectivity was higher in 20% Co/HSA than in 20% Co/Si-MMS. In the effect of n-hexane added in syngas, the selectivities of C5+ and olefin were increased by comparing the supercritical phase reaction with the gas phase reaction in addition to reduce unexpected methane and carbon dioxide.

The esterification of the reactants of Jatropha oil and methanol added by propyleneglycol was done using p-TSA catalyst. And then the emulsification of triglyceride and methanol was conduced by 1.0vol% GMS. The emulsified reactants were transesterified at 65℃ using TMAH and mixed catalyst (50wt%-TMAH+50wt%-NaOH) respectively. The esterification conversion at the 1:8 molar ratio of free fatty acid to methanol using 8.0wt% p-TSA was 94.7% within 80min. The overall conversion at the 1:8 molar ratio of mixed fat(50wt% Beef Tallow) to methanol and 65℃ using mixed catalyst was 95.4% The cloud point of Biodiesel decreased with the addition of petroleum diesel.

A visible-light photoactive photocatalyst was synthesized successfully by means of cogrinding of anatase- in ambient, followed by heat-treatment at in air environment. In general, it is well known that the grinding-operation induces phase transformation of a- to rutile . This study investigates the influence of the amount of gas on the phase transformation rate of a- and enhancement of visible-light photocatalytic activity, and also examines the relation between the photocatalytic activity and the period of grinding time. The phase transformation rate of a- to rutile is retarded with the amount of NH3 injected. And the visible-light photocatalytic activity of samples, was more closely related to the period of grinding time than amount injected, which means that the doping amount of nitrogen into more effective to mechanical energy than amount injected. XRD, XPS, FT-IR, UV-vis, Specific surface area (SSA), NOx decomposition techniques are employed to verify above results more clearly.

The electrocatalytic behavior of the PtCo catalyst supported on the multi-walled carbon nanotubes (MWNTs) has been evaluated and compared with commercial Pt/C catalyst in a polymer electrolyte membrane fuel cell(PEMFC). A PtCo/MWNTs electrocatalyst with a Pt:Co atomic ratio of 79:21 was synthesized and applied to a cathode of PEMFC. The structure and morphology of the synthesized PtCo/MWNTs electrocatalysts were characterized by X-ray diffraction and transmission electron microscopy. As a result of the X-ray studies, the crystal structure of a PtCo particle was determined to be a face-centered cubic(FCC) that was the same as the platinum structure. The particle size of PtCo in PtCo/MWNTs and Pt in Pt/C were 2.0 nm and 2.7 nm, respectively, which were calculated by Scherrer's formula from X-ray diffraction data. As a result we concluded that the specific surface activity of PtCo/MWNTs is superior to Pt/C's activity because of its smaller particle size. From the electrochemical impedance measurement, the membrane electrode assembly(MEA) fabricated with PtCo/MWNTs showed smaller anodic and cathodic activation losses than the MEA with Pt/C, although ohmic loss was the same as Pt/C. Finally, from the evaluation of cyclic voltammetry(CV), the unit cell using PtCo/MWNTs as the cathode electrocatalyst showed slightly higher fuel cell performance than the cell with a commercial Pt/C electrocatalyst.

In chemistry, the study of sonochemistry is concerned with understanding the effect of sonic waves and wave properties on chemical systems. In the area of chemical kinetics, it has been observed that ultrasound can greatly enhance chemical reactivity in a number of systems by as much as a million-fold. Nano-technology is a super microscopic technology in which structures of 100 nanometers or smaller can be investigated. This technology has been used to develop TiO2 materials and TiO2 devices of that size. Thus far, electrochemistry methods and photochemistry methods have generally been used to create TiO2 nano-size particles. However, these methods are complicated and create pollutants as a by-product. In the present study, nano-scale silver particles (5 nm) were prepared in a sonochemistry method. Sonochemistry deals with mechanical energy that is provided by the collapse of cavitation bubbles that form in solutions during exposure to ultrasound. TiO2 powders 25 nm in size doped with Ag were formed using an ultrasonic sound technique. The experimental results showed the high possibility of removing pollution through the action of a photocatalyst. This powder synthesis technique can be considered as an environmentally friendly powder-forming processing owing to its energy saving characteristics.

On cold start operation of a gasoline engine, a catalyst shows poor performance before it reaches activation temperature. Therefore, fast warmup of the catalyst is very crucial to reduce harmful emissions. In this study, an appropriate control strategy is investigated to increase exhaust gas temperature through changes of exhaust valve timing. An advance of exhaust valve timing decreases residual gas in cylinders due to decrease of valve overlap period. A control strategy of proper valve timing is suggested in order to achieve fast light-off of the catalyst and stable operation of the engine in a cold start and idle operation.

Treatment characteristics of benzene were investigated by using a fixed bed reactor system applying a hybrid method over composites of photocatalyst and adsorbent. Various composites were made by mixing photocatalyst with adsorbent, such as activated carbon, activated carbon fiber, and sludge. Performance tests were conducted with benzene concentrations of 1,000～3,000 ppm, Benzene flow rates of 50～100cc/min, and packing weights of 14～24g for the various composite samples. The property of benzene treatment was analyzed concerning BET, SEM, pH, and the conversion efficiency. It was concluded by experimental results that the benzene conversion efficiency of a hybrid method was much higher than that of a photocatalyst only method showing a conversion efficiency range between 13% and 65%. It was also found that the comprehensive feasibility study of the hybrid method would be needed with consideration of various factors including additional expenses.

The synthesis of cyclic carbonate from butyl glycidyl ether (BGE) and carbon dioxide was performed in the presence of three different types of ionic liquid : quarternary ammonium salt, alkyl pyridinium salt, and alkylimidazolium salt. Ionic liquids of different alkyl groups (C3, C4, C6 and C8) and anions (Cl-, Br- and I-) were used for the reaction which was carried out in a batch autoclave reactor at 60~120℃. The catalytic activity was increased with increasing alkyl chain length in the order of C3 〈 C4 〈 C6. But the ionic liquid with longer alkyl chain length (C8) decreased the conversion of BGE because it is too bulky to form an intermediate with BGE. For the counter anion of the ionic liquid catalysts, the BGE conversion decreased in the order Cl- 〉 Br- 〉 I-.

the less-reported gaseous studies have primarily dealt with chemical process stream concentrations than indoor air quality (IAQ) concentration levels. Accordingly, the current study was conducted to establish the feasibility of applying visible-light-induced TiO₂ doped with sulfur (S) element to cleanse toluene and ehtyl benzene at IAQ levels. The S-doped TiO₂ was prepared by applying two popular processes and two well-known methods. For both target compounds, the two coating methods exhibited different photocatalytic oxidation (PCO) efficiency. Similarly, the two S-doping processes showed different PCO efficiency. These results indicate that the coating method and doping process are important parameters which can influence PCO efficiency. Meanwhile, it was found that the PCO efficiency of ethyl benzene was higher than that of toluene. In addition, the degradation efficiency of the target compounds increased as the relative humidity (RH) decreased. The PCO efficiency varied from 44% to 74% for toluene and from 68% to 95%, as the RH decreased. Consequently, it is suggested that with appropriate RH conditions, the visible-light-assisted photocatalytic systems can also become an important tool for improving IAQ.

The esterification of free fatty acid in Jatropha oil added by propylene glycol using p-TSA catalyst was done, and then the transesterification of Jatropha oil added by 1.0vol% GMS as an emulsifier using TMAH, and mixed catalyst(60wt%-TMAH+ 40wt%-KOH) respectively was followed at 60℃. The esterification conversion at the 1:8 molar ratio of free fatty acid to methanol using 8.0wt% p-TSA was 94.7% within 60min. The overall conversion at the 1:8 molar ratio of Jatropha oil to methanol and 60℃ using mixed catalyst was 95.4%. The kinematic viscosity of Biodiesel using TMAH and mixed catalyst in 24h met the ASTM D-6751 above 30℃, and showed a little more than its criterion.

The aim of this study is to investigate the potential of Al-MCM-48 for the dioxin decomposition reaction. As a model reaction for the dioxin decomposition, chlorobenzene was decomposed over Al-MCM-48 in a fixed-bed reactor. Characteristics of catalysts were determined by N₂ adsorption-desorption isotherms (BET), and NH₃-temperature programmed desorption (NH₃-TPD), X-ray diffraction (XRD) methods. The activity of Al-MCM-48 (15) was higher than that of Al-MCM-48 (60) due to its higher amount acid sites. It can be concluded from the results of this study that Al-MCM-48 with higher acidity can be effectively applied to dioxin decomposition catalyst.

The importance of indoor air environment gets higher because time of staying in indoor such as house or car become longer due to a change of the life pattern on human society. One of major pollution sources, VOCs or odor could be reduced or controlled by using adsorbent. It may be valuable for used catalyst to be applied in the adsorption of VOCs or odor. This could reduce the cost of adsorbent. In this work, the potential of used zeolites such as HZSM-5 catalyst and FCC catalyst as an adsorbent for removing acetaldehyde was investigated. Their adsorptive performances were compared with those of active carbon and MCM-41. The removal performace of used HZSM-5 was similar to that of active carbon due to its higher surface area. But used-FCC catalyst showed the lowest performance. These results suggest that used HZSM-5 can be applied to cheap adsorbent for acetaldehyde removal.

In this study, we attempt to analyze biofilter"s removal efficiency for volatile organic compounds from paint factory. this experiment conducted in a pilot plant with microorganisms immobilized polyurethane foam. 7 main components (Toulene, MEK, MIBK, o-Xylene, m-Xylene, Butyl acetate, Ethyl benzene) emitted from factory ventilation opening were analyzed. During the test period, the biofilter treated VOCs in 5 seconds (EBCT) and pressure drop was less than 30 ㎜H₂O/m in media. Removal efficiencies of all components were between 80~90% in 10 days of operation and higher than 94% after 40 days. The result of this experiment shows that biofilter can be useful technology for VOCs removal in the paint industry.

Pt-loaded carbon black for the catalyst of a PEM fuel cell was synthesized with different molar ratios of polyvinylpyrrolidone and H2PtCl6 solution to improve the dispersion of Pt nanoparticles on carbon black and decrease the size of Pt nanoparticles. From transmission electron microscopy results, Pt nanoparticles of a size of approximately 2 nm were highly dispersed when the polyvinylpyrrolidone concentration was 10mM. The electrochemical activity of the synthesized Pt/C catalysts was investigated by cyclic voltammetry, showing that the as-synthesized Pt-loaded carbon black catalyst had the best activity at a polyvinylpyrrolidone concentration of 10 mM.

Nano-sized TiO2-60 wt% SrO composite powders were synthesized by a sol-gel method using titanium isopropoxide and Sr(OH)2 · 8H2O as precursors. 3, -5, -7 wt%Ag spot-coated TiO2-60 wt% SrO composite powders were synthesized by a Ag electroless deposition method using TiO2-60 wt% SrO composite powders calcined at 1050˚C, which mainly exhibited the SrTiO3phase. However, a small number of rutile TiO2, Sr2TiO4 and SrO2 phases were also detected. In the Ag spot-coated powders synthesized by electroless deposition, nano-sized particles about 5-25 nm in diameter adhered to the TiO2-60 wt% SrO composite powders. The photocatalytic activity of Ag spot-coated TiO2-SrO and TiO2-SrO composite powders for degradation of phenol showed that all of TiO2-SrO composite powders were highly active under UV light irradiation. 7 wt%Ag spot-coated TiO2-60wt.%SrO composite powders had a relatively higher photocatalytic activity than did TiO2-SrO composite powders under visible light.

In this study, we attempted to analyze removal efficiency of odorous compounds emitted from Grit chamber and night soil treatment facility using biofilter with microbial catalyst. Air dilution method was used for mixed odor gases analysis. UV-vis spectrophotometer for ammonia and Hydrogen sulfide, Methyl mercaptan, Dimethyl sulfide, Dimethyl disulfide were measured using GC/PFPD. Sample gases were collected at the inlet and outlet of biofilter. The analysis result showed that average concentration of major odorous compounds were ammonia with 5,100 ppb and hydrogen sulfide with 797 ppb from grit chamber and ammonia with 1,407 ppb and hydrogen sulfide with 2,475 ppb from night soil treatment facility. Hydrogen sulfide was the most influential compound of malodor based on odor quotient index. The average dilution threshold of odor was 923 at grit-chamber and 1,267 at night soil treatment facility. The removal efficiency of odorous compounds from sewage treatment facility were more than 94% using polyurethane foam biofilter within empty bed contact time 3sec. The emitted concentration to the atmosphere was satisfied with the criterion of the offensive odor control law.

A ZrO2 coating solution containing ZrO2 photo-catalysis, which is transparent in visible light, was prepared by the hydrolysis of alkoxide, and thin films on the SiO2 glass substrate were formed in a dipcoating method. These thin films were heat-treated at temperatures ranging from 250˚C-800˚C and their characteristics were subjected to thermal analysis, XRD, spectrometry, SEM, EDS, contact angle measurement, and AFM. Tetragonal ZrO2 phase was found in the thin film heat treated at 450˚C, and anatase TiO2 phase was detected in the thin film heat-treated at 600˚C and above. The thickness of the films was approximately 300 nm, and the roughness was 0.66 nm. Thus, the film properties are excellent. The films are super hydrophilic with a contact angle of 4.0˚; moreover, they have self-cleaning effect due to the photo catalytic property of anatase TiO2.

To increase pot life in the formulation mixed with bisphenol F epoxy resin, anhydride-based curing agent, and imidazole-based curing accelerator powders as a paste material for high-speed RFID chip bonding, size variation of the imidazole-based powders and a coating method of the powders were adopted in this study. In experiment with regard to the size variation, the pot life was not outstandingly increased. Through the idea using the coating method, however, the pot life was increased up to 4.25 times in comparison with the addition of initial imidazole-based powders. Consequently, successive bonding of RFID chip could be performed with very short time of 5sec using the suggested formulation having improved pot life.

Dipalmitoyl phosphatidyl choline and p-nitrophenyl palmitate were directly sonicated in acidic water for 6 minutes to give clear stock solutions. The catalytic hydrolysis of p-nitrophenyl palmitate was studied at 30-50℃ in the presence of unilamellar vesicle and mixture of unilamellar and multilamellar aggregates. The difference of reaction rate between unilamellar and multilamellar was observed. The rate of unilamellar reaction compared to the rate of mixture reaction showed more catalytic effect. The phase transition temperature of vesicle was measured at 37-44℃.