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In Kyu Song - One of the best experts on this subject based on the ideXlab platform.
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effect of Calcination Temperature of mesoporous nickel alumina catalysts on their catalytic performance in hydrogen production by steam reforming of liquefied natural gas lng
Journal of Industrial and Engineering Chemistry, 2010Co-Authors: Jeong Gil Seo, Min Hye Youn, Jin Suk Chung, In Kyu SongAbstract:Abstract Mesoporous nickel–alumina (Ni–A-NS) catalysts prepared by a non-ionic surfactant-templating method were calcined at various Temperatures for use in hydrogen production by steam reforming of liquefied natural gas (LNG). The effect of Calcination Temperature of nickel–alumina catalysts on their physicochemical properties and catalytic activity for steam reforming of LNG was investigated. Nickel oxide species were finely dispersed on the surface of Ni–A-NS catalysts through the formation of nickel aluminate phase. Reducibility, nickel surface area, and nickel dispersion of Ni–A-NS catalysts decreased with increasing Calcination Temperature. In the steam reforming of LNG, both LNG conversion and hydrogen composition in dry gas decreased with increasing Calcination Temperature of Ni–A-NS catalysts. Nickel surface area and reducibility of Ni–A-NS catalysts were well correlated with catalytic performance of the catalysts. Among the catalysts tested, Ni–A-NS700 (nickel–alumina catalyst calcined at 700 °C) with the highest nickel surface area and the highest reducibility exhibited the best catalytic performance.
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hydrogen production by steam reforming of liquefied natural gas lng over ni al2o3 zro2 xerogel catalysts effect of Calcination Temperature of al2o3 zro2 xerogel supports
International Journal of Hydrogen Energy, 2009Co-Authors: Min Hye Youn, Jin Suk Chung, Sunyoung Park, In Kyu SongAbstract:Abstract Al 2 O 3 –ZrO 2 (AZ) xerogel supports prepared by a sol-gel method were calcined at various Temperatures. Ni/Al 2 O 3 –ZrO 2 (Ni/AZ) catalysts were then prepared by an impregnation method for use in hydrogen production by steam reforming of liquefied natural gas (LNG). The effect of Calcination Temperature of AZ supports on the catalytic performance of Ni/AZ catalysts in the steam reforming of LNG was investigated. Crystalline phase of AZ supports was transformed in the sequence of amorphous γ-Al 2 O 3 and amorphous ZrO 2 → θ-Al 2 O 3 and tetragonal ZrO 2 → (θ + α)-Al 2 O 3 and (tetragonal + monoclinic) ZrO 2 → α-Al 2 O 3 and (tetragonal + monoclinic) ZrO 2 with increasing Calcination Temperature from 700 to 1300 °C. Nickel oxide species were strongly bound to γ-Al 2 O 3 and θ-Al 2 O 3 in the Ni/AZ catalysts through the formation of solid solution. In the steam reforming of LNG, both LNG conversion and hydrogen composition in dry gas showed volcano-shaped curves with respect to Calcination Temperature of AZ supports. Nickel surface area of Ni/AZ catalysts was well correlated with catalytic performance of the catalysts. Among the catalysts tested, Ni/AZ1000 (nickel catalyst supported on AZ support that had been calcined at 1000 °C) with the highest nickel surface area showed the best catalytic performance. Well-developed and pure tetragonal phase of ZrO 2 in the AZ1000 support played an important role in the adsorption of steam and the subsequent spillover of steam from the support to the active nickel.
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effect of Calcination Temperature of mesoporous alumina xerogel ax supports on hydrogen production by steam reforming of liquefied natural gas lng over ni ax catalysts
International Journal of Hydrogen Energy, 2008Co-Authors: Jeong Gil Seo, Min Hye Youn, Sunyoung Park, In Kyu SongAbstract:Abstract Mesoporous alumina xerogel (AX) supports prepared by a sol–gel method were calcined at various Temperatures. Ni/mesoporous alumina xerogel (Ni/AX) catalysts were then prepared by an impregnation method, and were applied to the hydrogen production by steam reforming of liquefied natural gas (LNG). The effect of Calcination Temperature of AX supports on the catalytic performance of Ni/AX catalysts in the steam reforming of LNG was investigated. Physical and chemical properties of AX supports and Ni/AX catalysts were strongly influenced by the Calcination Temperature of AX supports. Crystalline structure of AX supports was transformed in the sequence of γ-alumina → (γ + θ)-alumina → θ-alumina → (θ + α)-alumina with increasing Calcination Temperature from 700 to 1000 °C. Nickel species were strongly bonded to the divalent vacancy of γ-alumina, (γ + θ)-alumina, and θ-alumina through the formation of nickel aluminate phase. In the steam reforming of LNG, both LNG conversion and hydrogen composition in dry gas showed volcano-shaped curves with respect to Calcination Temperature of AX supports. Among the catalysts tested, Ni/AX-900 (nickel catalyst supported on AX that had been calcined at 900 °C) showed the best catalytic performance. The smallest nickel crystalline size and the strongest nickel–alumina interaction were responsible for high catalytic performance of Ni/AX-900 catalyst in the steam reforming of LNG.
Min Hye Youn - One of the best experts on this subject based on the ideXlab platform.
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effect of Calcination Temperature of mesoporous nickel alumina catalysts on their catalytic performance in hydrogen production by steam reforming of liquefied natural gas lng
Journal of Industrial and Engineering Chemistry, 2010Co-Authors: Jeong Gil Seo, Min Hye Youn, Jin Suk Chung, In Kyu SongAbstract:Abstract Mesoporous nickel–alumina (Ni–A-NS) catalysts prepared by a non-ionic surfactant-templating method were calcined at various Temperatures for use in hydrogen production by steam reforming of liquefied natural gas (LNG). The effect of Calcination Temperature of nickel–alumina catalysts on their physicochemical properties and catalytic activity for steam reforming of LNG was investigated. Nickel oxide species were finely dispersed on the surface of Ni–A-NS catalysts through the formation of nickel aluminate phase. Reducibility, nickel surface area, and nickel dispersion of Ni–A-NS catalysts decreased with increasing Calcination Temperature. In the steam reforming of LNG, both LNG conversion and hydrogen composition in dry gas decreased with increasing Calcination Temperature of Ni–A-NS catalysts. Nickel surface area and reducibility of Ni–A-NS catalysts were well correlated with catalytic performance of the catalysts. Among the catalysts tested, Ni–A-NS700 (nickel–alumina catalyst calcined at 700 °C) with the highest nickel surface area and the highest reducibility exhibited the best catalytic performance.
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hydrogen production by steam reforming of liquefied natural gas lng over ni al2o3 zro2 xerogel catalysts effect of Calcination Temperature of al2o3 zro2 xerogel supports
International Journal of Hydrogen Energy, 2009Co-Authors: Min Hye Youn, Jin Suk Chung, Sunyoung Park, In Kyu SongAbstract:Abstract Al 2 O 3 –ZrO 2 (AZ) xerogel supports prepared by a sol-gel method were calcined at various Temperatures. Ni/Al 2 O 3 –ZrO 2 (Ni/AZ) catalysts were then prepared by an impregnation method for use in hydrogen production by steam reforming of liquefied natural gas (LNG). The effect of Calcination Temperature of AZ supports on the catalytic performance of Ni/AZ catalysts in the steam reforming of LNG was investigated. Crystalline phase of AZ supports was transformed in the sequence of amorphous γ-Al 2 O 3 and amorphous ZrO 2 → θ-Al 2 O 3 and tetragonal ZrO 2 → (θ + α)-Al 2 O 3 and (tetragonal + monoclinic) ZrO 2 → α-Al 2 O 3 and (tetragonal + monoclinic) ZrO 2 with increasing Calcination Temperature from 700 to 1300 °C. Nickel oxide species were strongly bound to γ-Al 2 O 3 and θ-Al 2 O 3 in the Ni/AZ catalysts through the formation of solid solution. In the steam reforming of LNG, both LNG conversion and hydrogen composition in dry gas showed volcano-shaped curves with respect to Calcination Temperature of AZ supports. Nickel surface area of Ni/AZ catalysts was well correlated with catalytic performance of the catalysts. Among the catalysts tested, Ni/AZ1000 (nickel catalyst supported on AZ support that had been calcined at 1000 °C) with the highest nickel surface area showed the best catalytic performance. Well-developed and pure tetragonal phase of ZrO 2 in the AZ1000 support played an important role in the adsorption of steam and the subsequent spillover of steam from the support to the active nickel.
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effect of Calcination Temperature of mesoporous alumina xerogel ax supports on hydrogen production by steam reforming of liquefied natural gas lng over ni ax catalysts
International Journal of Hydrogen Energy, 2008Co-Authors: Jeong Gil Seo, Min Hye Youn, Sunyoung Park, In Kyu SongAbstract:Abstract Mesoporous alumina xerogel (AX) supports prepared by a sol–gel method were calcined at various Temperatures. Ni/mesoporous alumina xerogel (Ni/AX) catalysts were then prepared by an impregnation method, and were applied to the hydrogen production by steam reforming of liquefied natural gas (LNG). The effect of Calcination Temperature of AX supports on the catalytic performance of Ni/AX catalysts in the steam reforming of LNG was investigated. Physical and chemical properties of AX supports and Ni/AX catalysts were strongly influenced by the Calcination Temperature of AX supports. Crystalline structure of AX supports was transformed in the sequence of γ-alumina → (γ + θ)-alumina → θ-alumina → (θ + α)-alumina with increasing Calcination Temperature from 700 to 1000 °C. Nickel species were strongly bonded to the divalent vacancy of γ-alumina, (γ + θ)-alumina, and θ-alumina through the formation of nickel aluminate phase. In the steam reforming of LNG, both LNG conversion and hydrogen composition in dry gas showed volcano-shaped curves with respect to Calcination Temperature of AX supports. Among the catalysts tested, Ni/AX-900 (nickel catalyst supported on AX that had been calcined at 900 °C) showed the best catalytic performance. The smallest nickel crystalline size and the strongest nickel–alumina interaction were responsible for high catalytic performance of Ni/AX-900 catalyst in the steam reforming of LNG.
Jeong Gil Seo - One of the best experts on this subject based on the ideXlab platform.
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effect of Calcination Temperature of mesoporous nickel alumina catalysts on their catalytic performance in hydrogen production by steam reforming of liquefied natural gas lng
Journal of Industrial and Engineering Chemistry, 2010Co-Authors: Jeong Gil Seo, Min Hye Youn, Jin Suk Chung, In Kyu SongAbstract:Abstract Mesoporous nickel–alumina (Ni–A-NS) catalysts prepared by a non-ionic surfactant-templating method were calcined at various Temperatures for use in hydrogen production by steam reforming of liquefied natural gas (LNG). The effect of Calcination Temperature of nickel–alumina catalysts on their physicochemical properties and catalytic activity for steam reforming of LNG was investigated. Nickel oxide species were finely dispersed on the surface of Ni–A-NS catalysts through the formation of nickel aluminate phase. Reducibility, nickel surface area, and nickel dispersion of Ni–A-NS catalysts decreased with increasing Calcination Temperature. In the steam reforming of LNG, both LNG conversion and hydrogen composition in dry gas decreased with increasing Calcination Temperature of Ni–A-NS catalysts. Nickel surface area and reducibility of Ni–A-NS catalysts were well correlated with catalytic performance of the catalysts. Among the catalysts tested, Ni–A-NS700 (nickel–alumina catalyst calcined at 700 °C) with the highest nickel surface area and the highest reducibility exhibited the best catalytic performance.
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effect of Calcination Temperature of mesoporous alumina xerogel ax supports on hydrogen production by steam reforming of liquefied natural gas lng over ni ax catalysts
International Journal of Hydrogen Energy, 2008Co-Authors: Jeong Gil Seo, Min Hye Youn, Sunyoung Park, In Kyu SongAbstract:Abstract Mesoporous alumina xerogel (AX) supports prepared by a sol–gel method were calcined at various Temperatures. Ni/mesoporous alumina xerogel (Ni/AX) catalysts were then prepared by an impregnation method, and were applied to the hydrogen production by steam reforming of liquefied natural gas (LNG). The effect of Calcination Temperature of AX supports on the catalytic performance of Ni/AX catalysts in the steam reforming of LNG was investigated. Physical and chemical properties of AX supports and Ni/AX catalysts were strongly influenced by the Calcination Temperature of AX supports. Crystalline structure of AX supports was transformed in the sequence of γ-alumina → (γ + θ)-alumina → θ-alumina → (θ + α)-alumina with increasing Calcination Temperature from 700 to 1000 °C. Nickel species were strongly bonded to the divalent vacancy of γ-alumina, (γ + θ)-alumina, and θ-alumina through the formation of nickel aluminate phase. In the steam reforming of LNG, both LNG conversion and hydrogen composition in dry gas showed volcano-shaped curves with respect to Calcination Temperature of AX supports. Among the catalysts tested, Ni/AX-900 (nickel catalyst supported on AX that had been calcined at 900 °C) showed the best catalytic performance. The smallest nickel crystalline size and the strongest nickel–alumina interaction were responsible for high catalytic performance of Ni/AX-900 catalyst in the steam reforming of LNG.
Sung Hong Hahn - One of the best experts on this subject based on the ideXlab platform.
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variation of structural and optical properties of sol gel tio2 thin films with catalyst concentration and Calcination Temperature
Materials Letters, 2003Co-Authors: Sung Hong HahnAbstract:TiO2 thin films were prepared on quartz glass by sol-gel process and their structural and optical properties were examined at various catalyst concentrations and Calcination Temperatures. The as-deposited TiO2 thin films are amorphous, and they transform into the anatase phase at 400–600 °C, and into the anatase–rutile phase at 800 °C, and further into the rutile phase at 1000 °C. The Temperature of phase transformation is decreased with the concentration of catalyst HCl. The crystallite size of TiO2 thin films is increased with increasing Calcination Temperature and catalyst concentration. The secondary particles in the TiO2 thin films grow by intra-agglomerate densification below 800 °C, whereas they grow by inter-agglomerate densification above 800 °C. The deposited TiO2 thin films have high transparency in the visible range. The transmittance of the films calcined at 800 and 1000 °C are significantly reduced in the wavelength range of 300–800 nm due to the change of crystallite phase and increased particle size. The refractive index of TiO2 thin films is increased with increasing Calcination Temperature and catalyst concentration. On the other hand, the porosity of TiO2 thin film is decreased.
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influence of Calcination Temperature on structural and optical properties of tio2 thin films prepared by sol gel dip coating
Materials Letters, 2002Co-Authors: Dong Jin Kim, Sung Hong Hahn, Eui Jung KimAbstract:TiO2 thin films were prepared by sol–gel dip coating and their structural and optical properties were examined at various Calcination Temperatures. The X-ray diffraction (XRD) results showed that TiO2 thin film calcined at 300 °C was amorphous, and transformed into the anatase phase at 400 °C, and further into rutile phase at 1000 °C. The phase transformation Temperature has been dependent upon the concentration of catalyst HCl. The crystallite size of TiO2 thin films was increased with increasing Calcination Temperature. The micro-particles in the films grew by intra-agglomerate densification below 1000 °C, whereas they grew by inter-agglomerate densification above 1000 °C. The transmittance of the films calcined at 1000 and 1100 °C was reduced significantly in the wavelength range of about 300–700 nm due to the change of crystallite phase and composition in the films. The refractive index of TiO2 thin films was increased with increasing Calcination Temperature, and the film thickness and the porosity of TiO2 thin films were decreased.
Jin Suk Chung - One of the best experts on this subject based on the ideXlab platform.
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effect of Calcination Temperature of mesoporous nickel alumina catalysts on their catalytic performance in hydrogen production by steam reforming of liquefied natural gas lng
Journal of Industrial and Engineering Chemistry, 2010Co-Authors: Jeong Gil Seo, Min Hye Youn, Jin Suk Chung, In Kyu SongAbstract:Abstract Mesoporous nickel–alumina (Ni–A-NS) catalysts prepared by a non-ionic surfactant-templating method were calcined at various Temperatures for use in hydrogen production by steam reforming of liquefied natural gas (LNG). The effect of Calcination Temperature of nickel–alumina catalysts on their physicochemical properties and catalytic activity for steam reforming of LNG was investigated. Nickel oxide species were finely dispersed on the surface of Ni–A-NS catalysts through the formation of nickel aluminate phase. Reducibility, nickel surface area, and nickel dispersion of Ni–A-NS catalysts decreased with increasing Calcination Temperature. In the steam reforming of LNG, both LNG conversion and hydrogen composition in dry gas decreased with increasing Calcination Temperature of Ni–A-NS catalysts. Nickel surface area and reducibility of Ni–A-NS catalysts were well correlated with catalytic performance of the catalysts. Among the catalysts tested, Ni–A-NS700 (nickel–alumina catalyst calcined at 700 °C) with the highest nickel surface area and the highest reducibility exhibited the best catalytic performance.
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hydrogen production by steam reforming of liquefied natural gas lng over ni al2o3 zro2 xerogel catalysts effect of Calcination Temperature of al2o3 zro2 xerogel supports
International Journal of Hydrogen Energy, 2009Co-Authors: Min Hye Youn, Jin Suk Chung, Sunyoung Park, In Kyu SongAbstract:Abstract Al 2 O 3 –ZrO 2 (AZ) xerogel supports prepared by a sol-gel method were calcined at various Temperatures. Ni/Al 2 O 3 –ZrO 2 (Ni/AZ) catalysts were then prepared by an impregnation method for use in hydrogen production by steam reforming of liquefied natural gas (LNG). The effect of Calcination Temperature of AZ supports on the catalytic performance of Ni/AZ catalysts in the steam reforming of LNG was investigated. Crystalline phase of AZ supports was transformed in the sequence of amorphous γ-Al 2 O 3 and amorphous ZrO 2 → θ-Al 2 O 3 and tetragonal ZrO 2 → (θ + α)-Al 2 O 3 and (tetragonal + monoclinic) ZrO 2 → α-Al 2 O 3 and (tetragonal + monoclinic) ZrO 2 with increasing Calcination Temperature from 700 to 1300 °C. Nickel oxide species were strongly bound to γ-Al 2 O 3 and θ-Al 2 O 3 in the Ni/AZ catalysts through the formation of solid solution. In the steam reforming of LNG, both LNG conversion and hydrogen composition in dry gas showed volcano-shaped curves with respect to Calcination Temperature of AZ supports. Nickel surface area of Ni/AZ catalysts was well correlated with catalytic performance of the catalysts. Among the catalysts tested, Ni/AZ1000 (nickel catalyst supported on AZ support that had been calcined at 1000 °C) with the highest nickel surface area showed the best catalytic performance. Well-developed and pure tetragonal phase of ZrO 2 in the AZ1000 support played an important role in the adsorption of steam and the subsequent spillover of steam from the support to the active nickel.