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- 저자 : 하백현 ( Jeong Kwon Suh (검색결과 5 건)
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전이 금속 산화물이 담지된 La / Al 복합산화물 촉매상에서의 메탄 연소반응
서정권,하백현,고재천,이정민 ( Jeong Kwon Suh,Baik Hyon Ha,Jae Cheon Koh,Jung Min Lee ) 한국화학공학회 1993 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.31 No.6
Combustion catalysts were prepared by the impregnation of transition metal oxide on La/Al oxide(Al₂O₃/La₂O₃=19), and then calcined in air. Methane combustion was carried out using these catalysts. X-ray diffraction analysis indicates that La/Al oxide was crystallized from amorphous form into La-β-Al₂O₃ phase above 1200℃. Crystallization was accelerated by the addition of copper on La/Al oxide, but it was retarded by the addition of chromium on La/Al oxide. The copper content of the surface of CuO-La/Al oxide decreased as the calcination temperature increased. This result indicates the formation of solid solution. In case of Cr₂O₃-La/Al oxide, Cr₂O₃mainly existed on the catalyst surface. The activities of catalysts calcined at 1200℃ appeared as the following order; CuO, Cr₂O₃>Fe₂O₃>MnO>CoO>NiO. The catalytic activity of CuO-La/Al oxide decreased as the calcination temperature increased. However the catalytic activity of Cr₂O₃-La/Al oxide was still maintained after calcination at 1400℃.
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크롬 및 구리가 담지된 La2O3 / Al2O3 계 복합산화물 촉매의 구조 및 열안정성
서정권,하백현 ( Jeong Kwon Suh,Baik Hyon Ha ) 한국화학공학회 1994 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.32 No.6
The structure and thermal properties of Cr and Cu added La₂O₃/Al₂O₃ system were investigated using XRD, BET, ESCA, TEM and DTA. During calcination the addition of chromium retarded the phase transition of La-β-Al₂O₃ and improved the thermal stability of La₂O₃/Al₂O₃ system at highly temperature. However the addition of copper on La₂O₃/Al₂O₃ system accelerated the phase transition of support. The surface area after being calcined at 1,200℃ for 2 hours was 40 ㎡/g for (Cr₂O₃) (La₂O₃) (Al₂O₃)_(19) oxide and 10 ㎡/g for (CuO)(La₂O₃)(Al₂O₃)_(19) oxide. The sintering of La₂O₃/Al₂O₃ system at 1,000℃ proceeded via surface diffusion and was not influenced by the Cr addition. The sintering of Cu added La₂O₃/Al₂O₃ system proceeded via viscous flow. The activation energy of the phase transition above 1,200℃ had a constant value about 600 kJ/㏖, regardless of the Cr and Cu addition.
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Vacuum Gas Oil 및 Carbazole 에 의해 코크화된 Co - Mo / γ- Al2O3 촉매의 활성저하에 대한 연구
정순용,진항교,김범식,이정민,서정권,하백현 ( Soon Yong Jeong,Hang Kyo Jin,Beom Sik Kim,Jung Min Lee,Jeong Kwon Suh,Baik Hyon Ha ) 한국공업화학회 1995 공업화학 Vol.6 No.2
A series of coked catalysts were prepared with Co-Mo/γ-Al₂O₃ hydrotreating catalyst by reacting with vacuum gas oil. The physical properties and catalytic activities of these coked catalysts were examined. A similar series of coked catalysts were prepared with carbazole added to vacuum gas oil, and the changes of physical properties and catalytic activities by nitrogen compounds were also examined. It was found that the amount of cake deposited on the surface of catalyst increases with increase of reaction temperature and reaction time. As amount of coke increases, pore volume and surface area decrease significantly. The order of reactivity of the fresh catalyst was: HDS > CNH > HYD > HDN. As the amount of coke increases, VGO-coked catalyst shows deactivation as order of HDN > CNH > HYD > HDS. Carbazole-coked catalyst shows much more deactivation in all reaction fuctionalities compared to the VGO-coked catalyst. Surface area and pore volume of carbazole-coked catalyst decrease much more than VGO-coked catalyst. These results can be explained as the severe plugging of pore mouth by the deposition of nitrogen compounds.
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