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TiO₂ 광촉매를 이용한 Trichloroethylene(TCE)와 광분해 반응
하진욱 한국산학기술학회 2000 한국산학기술학회논문지 Vol.1 No.2
Trichloroethylene(TCE)의 수용액 내에서 광분해 반응을 연구하였다. 광촉매 TiO₂의 표면특성은 XRD. SEM 및 BET를 사용하여 선행연구[23]에서 고찰하였으며 Aldrich TiO₂는 100% anatase KIER TiO₂는 100% rutile, Degussa에서 제조한 P25-TiO₂는 75% anatase와 25% rutile의 혼합구조(structure)를 가점을 알 수 있었다. 본 연구에서는 TCE 분해반응의 최적조건을 선정하기 위해여 광총매의 사용량, 분해반응시 혼합용액의 순환유속, TCE의 초기농도 및 광총매 TiO₂구조가 광분해 반응에 미치는 영향을 자세히 고찰하였다. 실험결과 증류슈 1 L를 기준으로 무게비 0.1 wt%의 광촉매를 사용하여 증류수와 TCE의 혼합용액을 200 ㏄/min로 순환시켰을 때 분해활성이 가장 좋음을 알 수 있었으며 일반적으로 anatase 구조가 rutile 구조를 가진 광촉매 보다 높은 활성을 보였다. 특히 anatasc와 rutile의 혼합구조를 가진 Degussa P25-TiO₂가 가장 좋은 활성을 보였으며 이는 작은 입자크기와 큰 비표면적에 기인한 결과로 보인다. The photocatalytic degradation of trichloroethylcne(TCE) in water on various types of TiO₂ was studied. Surface properties of TiO₂ were characterized by XRD, SEM, and BET in our previous work[23]. TiO₂ from Aldrich has 100% pure anatase. TiO₂ from KIER has 100% pure rutile structure. and P25-TiO₂ from Dagussa has mixed structure of anatase(75%) and rutile(25%). Firstly. optimum conditions for TCE degradation were examined in this study. Results showed that optimum loading amount of catalyst was 0.1 wt% and recirculation now rate of mixture(distilled water and TCE) was 200 ㏄/min. Secondly, the effect of TiO₂ structure on TCE degradation was examined. Results revealed that anatase structure generally has better photocatalytic activity than rutile structure. Especially, mixed structure(Degussa P25-TiO₂) has the highest activity due to small particle size and large specific surface area.
실리카에 담지된 메탈로센 촉매에서 실리카의 소성온도가 폴리에틸렌(PE) 중합에 미치는 영향
하진욱 순천향대학교 부설 산업기술연구소 1996 순천향 산업기술연구소논문집 Vol.2 No.1
Since the discovery of olefin polymerzation with Zigler-Natta catalysts, polyolefin has become one of the most important polymers in chemical industry. The discovery of new crystalline polymers was highly evaluated as "revolution of polymer science". In 1980, it was reported that metallocene could be activated with methylaluminoxane (MAO) and had high activity in polyethylene (PE) polymerization. However, even though homogeneous metallocene has high activity, it has some problems in chemical process (such as reactor fouling). To solve these problems supported metallocene has been studied from many other chemical groups by using silica (SiO2), alumina (A1203) and magnesia(MgO) support. Recently it is reported that thermal treatment of silica surface can controll hydroxyl group (OH-) on the silica surface which is an important functional group to load homogeneous meatallocene. It is known that loading amount of metallocene affects the catalytic activity. The purpose of this study is to find relationship between the amount of hydroxyl group on the silica surace and the loading amount of metallocene, and also to find relationship between the loading amount of metallocene and the catalytic activity in PE polymerization.
결정상과 분산도의 조절이 가능한 MoO<sub>3</sub>/SiO<sub>2</sub> 촉매의 제조 및 탈황반응특성 연구
하진욱,Ha, Jin-Wook 한국공업화학회 1999 공업화학 Vol.10 No.2
결정상과 분산도가 조절된 $MoO_3$/$SiO_2$ 담지촉매를 제조하여 촉매의 표면특성과 디벤조티오펜 탈황반응의 활성도를 고찰하였다. Mo의 표면담지량은 4 atoms $Mo/nm^2$이었으며, 실리카 표면 위에 형성된 $MoO_3$의 결정상은 sintered hexagonal, sintered orthorhombic, 및 dispersed hexagonal상이었다. XRD, Raman, 및 $O_2$ 흡착 결과 $MoO_3$의 표면분산도는 sintered hexagonal < sintered orthorhombic < dispersed hexagonal 순으로 증가하였다. TPR 결과 $MoO_3$ 결정은 $650^{\circ}C$에서 $MoO_2$로, $1000^{\circ}C$에서 Mo로 환원됨을 알 수 있었다. 디벤조티오펜 탈황반응을 30기압, $350{\sim}500^{\circ}C$ 온도범위에서 수행하였으며, 실험 결과 활성도는 $MoO_3$ 결정체의 $SiO_2$ 표면에서의 분산도에 비례하여 증가함을 알 수 있었다. Several series of morphologically controlled $MoO_3$/$SiO_2$ catalysts were prepared, characterized, and tested for hydrodesulfurization (HDS) of dibenzothiophene (DBT) activity. Molybdenum surface loaded with 4.0 atoms $Mo/nm^2$ was prepared as sintered hexagonal and sintered orthorhombic, as well as a novel "well dispersed hexagonal" phase. Characterization by XRD, Raman, and $O_2$ chemisorption results reveals that the dispersion of $MoO_3$ over silica depends on the final $MoO_3$ phase in the order of; sintered hexagonal < sintered orthorhombic < dispersed hexagonal phase. Temperature programmed reduction (TPR) results show that both bulk and dispersed microcrystalline of $MoO_3$ reduce to $MoO_2$ at $650^{\circ}C$ and to Mo metal at $1000^{\circ}C$. HDS of DBT was performed in a differential reactor at 30 atm over the temperature range $350{\sim}500^{\circ}C$. Activity of $MoO_3$/$SiO_2$ toward HDS of DBT is proportional to dispersion.
대기오염의 주요물질인 SOx 제거를 위한 수소첨가 탈황반응에 사용되는 MoO₃/SiO₂촉매의 표면특성에 대한 연구
하진욱 순천향대학교 부설 산업기술연구소 1998 순천향 산업기술연구소논문집 Vol.4 No.1
The morphology of silica supported catalysts, prepared by impregnation of ammonium heptamolybdate and for various surface loading up to 4 atom Mo/nm², was studied by XRD, TGA, BET, and O₂chemisorption. In addition to the orthorhombic phase, the behavior of the rarely studied hexagonal phase was fully characterized. At low loadings there appeared one stable dispersion. For high loaded catalysts there appeared three states: a metastable sintered hexagonal state, a well dispersed hexagonal state at moderate temperature calcination (300℃), and the sintered orthorhombic state at high temperature(500℃). Surface area(BET) of catalysts only depends on the surface loading and do not depend on the phase of MoO₃crystal over silica increases in the order of sintered hexagonal < sintered orthorhombic < dispersed hexagonal for high loaded catalysts.
전선 Cable에 유·무기 복합 난연 코팅에 의한 난연 상승에 관한 연구(Ⅱ)
하진욱 순천향대학교 부설 산업기술연구소 2004 순천향 산업기술연구소논문집 Vol.10 No.2
Polymeric materials are widely used in a variety of application. The products use the fields of electrical and electronic equipments, textiles and furnitures, car, trains, ships and airplanes as well as construction products in buildings. Special attention is always needed for their fire-safe use in the different applications because polymers are combustible by nature. Many different flame retardant methods can be used depending on the polymer itself, ptoduct type and the end-use application. The effect of coating which contains organicㆍinorganic flacme retardant on flame retardancy of XLPE cable was studied. TBBA, Mg(OH)_(2), AF100 S, Sb_(2)O_(3), Zinc Borate and urethane binder were formulated and used as hybrid coating agents. The properties of coated XLPE cable were investigated by using optical microscope and thermogravimetic analysis(TGA). The results of flammability test showed that optimum amounts of flame retardant were 10 to 15 wt% for Sb_(2)O_(3), 10 to 15 wt% for Zinc Borate, and 5 to 10 wt% for AF100 S. Flame retardancy of XLPE cable improved by hybrid coating due to inorganic-organic synergism.